Tuesday, 6 October 2026 · New Delhi
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Glossary · Z
38 terms defined in plain English, each with a link to articles that use it.
Zabt is the Mughal revenue method perfected by Sher Shah Suri and inherited by Akbar: land was measured, classified by fertility, and the state's demand fixed on the measured area rather than on fluctuating harvests. It replaced arbitrary plunder with a predictable, survey-based claim. For UPSC it is GS-1 medieval India: Mughal land-revenue systems.
Example: Sher Shah Suri's revenue reforms of 1540-45, including the rupiya, the Grand Trunk Road and the zabti survey.
The zabti system was Akbar's land-revenue settlement under Todar Mal: measured land was classified by fertility and the state's share fixed at one-third of the average produce over the preceding ten years, under the Ain-i-Dahsala. Payment could be in cash, and the demand stayed stable across seasons. For UPSC it is GS-1: Mughal administration, mansabdari's fiscal twin.
Example: Todar Mal's Ain-i-Dahsala, introduced in 1580.
Zahiruddin Muhammad Babur is the Timurid prince who founded the Mughal Empire in India after defeating Ibrahim Lodi at the First Battle of Panipat in 1526. His memoirs, the Baburnama, record his campaigns, gardens, and early observations of India. For UPSC, Babur opens the entire Mughal chapter of medieval history, covering its warfare, architecture, administration, and cultural synthesis.
Example: First Battle of Panipat, 1526
Zaibatsu is the name for the large family-controlled industrial and financial conglomerates that dominated Japan from the Meiji era to 1945, such as Mitsubishi, Mitsui, Sumitomo and Yasuda. Combining banks, factories and trading houses under family holding companies, they industrialised Japan in close alliance with the imperial state. The American occupation dissolved them after the Second World War, though successor keiretsu networks survive. For UPSC, the zaibatsu illustrate state-led industrialisation in GS-1 world history.
Example: Mitsubishi and Mitsui, the classic Meiji-era zaibatsu houses.
Zaid is the short summer catch-season between rabi harvest and kharif sowing, roughly March to June, grown where irrigation is available. Its crops include summer moong and urad, watermelon, cucumber, fodder and vegetables, and it adds a third crop to the annual cycle. For UPSC, zaid illustrates cropping-intensity gains and the role of assured water in squeezing an extra season from the land.
Example: Summer moong sown in April in western Uttar Pradesh gives farmers a quick pulse harvest before kharif paddy transplanting.
Giani Zail Singh was the seventh President of India, serving from 1982 to 1987, and the first Sikh to hold the office. Earlier Punjab’s Chief Minister and Union Home Minister, his presidency is remembered for the 1986 pocket veto of the Indian Post Office (Amendment) Bill, which he stalled by simply taking no action because he felt it threatened privacy. UPSC tests him in questions on the President’s veto powers and centre state relations.
Example: His pocket veto killed the Indian Post Office (Amendment) Bill, 1986, which would have given the state wide powers to intercept mail.
This refers to the pocket veto exercised by President Giani Zail Singh over the Indian Post Office (Amendment) Bill, 1986, which expanded postal interception powers. He neither signed nor returned the bill, letting it lapse indefinitely, since the Constitution sets no deadline for presidential assent. For UPSC, it is the textbook example of the pocket veto in Indian polity and of executive-legislature tension.
Example: Indian Post Office (Amendment) Bill, 1986
Zakat is one of the five pillars of Islam: an obligatory alms payment, usually 2.5 per cent of eligible savings and wealth, distributed to the poor, the needy and other categories of recipients. In medieval India the Delhi Sultans collected zakat from Muslims alongside taxes such as jizya, and Firuz Shah Tughlaq treated it as a formal state levy. For UPSC it matters in GS-1 medieval history on Sultanate fiscal administration and in GS-4 ethics under charity and redistribution.
Example: Firuz Shah Tughlaq's formal levy of zakat as state revenue in the Delhi Sultanate.
The Zakir Hussain Committee is the 1937 committee chaired by Dr. Zakir Hussain that gave detailed shape to Gandhi's Wardha Scheme of Basic Education (Nai Talim), proposing free, compulsory, craft-centered schooling in the mother tongue. Its 1938 report became the official blueprint for national education adopted by the Congress ministries. For UPSC, it links freedom-movement history with education policy and the idea of Nai Talim.
Example: Wardha Scheme of Basic Education, report 1938
Zamindari is the British land revenue system under which zamindars were recognised as proprietors of land and paid a fixed revenue demand to the state, through Lord Cornwallis's Permanent Settlement of 1793 in Bengal, Bihar and Orissa. Meant to guarantee stable revenue and create loyal landlords, it reduced peasants to tenants at will and is blamed for rural indebtedness. For UPSC it is core GS-1 modern history: always compare it with the ryotwari and mahalwari systems in land revenue answers.
Example: The Permanent Settlement of Bengal, 1793, under Lord Cornwallis.
The zamindari system was the British revenue arrangement, fixed permanently in Bengal in 1793, making zamindars proprietors who collected rent for the state. It created absentee landlordism and rack-renting of cultivators. For UPSC it is the exploitative baseline that post-independence abolition laws removed.
Example: The Permanent Settlement's creation of a parasitic landlord class is the system's defining critique.
Zamindars were the hereditary revenue intermediaries between the state and the peasantry in pre-colonial and colonial India, collecting land revenue and exercising local administrative and military functions under the Mughals and later the British. The Permanent Settlement made them legal landowners, and many became absentees who sublet to tenants at rack rents, deepening agrarian distress. For UPSC they appear in GS-1 answers on agrarian structure, peasant movements such as the Indigo Revolt and Deccan Riots, and post-independence zamindari abolition.
Example: The Rajas of Burdwan, among the great zamindari estates of Bengal under the Permanent Settlement.
Zamindars and intermediaries were the rent-collecting layers between the state and the cultivator under British revenue systems, especially the Permanent Settlement. They extracted high rents without cultivating, and their abolition was land reform's first component. For UPSC they represent the feudal agrarian structure independent India dismantled.
Example: The abolition laws of the 1950s resumed zamindari rights and vested land in the state for redistribution.
The Zamorin is the hereditary title of the rulers of Calicut (Kozhikode), the dominant maritime power on the Malabar Coast in the medieval period. The Zamorins controlled the pepper trade, and Vasco da Gama reached their court in 1498. For UPSC, the Zamorin frames medieval Indian Ocean commerce, the arrival of the Portuguese, and the economics of the spice trade.
Example: Vasco da Gama's arrival at Calicut, 1498
The Zaranj-Delaram highway is a 215 km Indian-built road in Afghanistan linking Zaranj on the Iranian border to Delaram on the Afghan ring road, constructed by India's Border Roads Organisation despite repeated insurgent attacks. It gives India and Afghanistan an alternate trade route bypassing Pakistan. For UPSC, it is the flagship example of Indian development diplomacy and regional connectivity strategy.
Example: Handed over to Afghanistan in January 2009
Zat is the personal rank of a Mughal mansabdar under Akbar's mansabdari system, denoting the holder's status, dignity and salary level, as distinct from sawar, which denoted the cavalry contingent he had to maintain. A mansab of 5,000 zat marked a high noble's personal standing in the imperial hierarchy, whatever troops he commanded. For UPSC it is a staple of GS-1 medieval history, routinely tested in questions on Akbar's administrative innovations.
Example: A mansabdar holding the rank of 5,000 zat under Akbar.
Zat and sawar are the twin components of the Mughal mansab rank under Akbar: zat fixed the noble's personal status and pay, while sawar fixed the number of horsemen he had to maintain and present for imperial inspection, the dagh. Separating dignity from military obligation let the emperor reward favourites with high zat without granting them large commands. For UPSC the pair is essential GS-1 medieval history for any question on the mansabdari system.
Example: A mansabdar of 5,000 zat and 5,000 sawar under Akbar.
Zawar in Rajasthan is a mining region near Udaipur recognized as the world's oldest known zinc-smelting site, where ancient Indians pioneered zinc extraction by the distillation process some two thousand years ago. Modern zinc-lead mining continues there today. For UPSC, Zawar is prime evidence of India's ancient metallurgical mastery and recurs in ancient history and economic geography questions.
Example: Hindustan Zinc Limited's mines at Zawar, Udaipur district
Zero and negative numbers entered world mathematics as formal entities through ancient India: Brahmagupta's Brahmasphutasiddhanta of 628 CE gave the first systematic rules for arithmetic with zero and negative quantities, building on the earlier Indian use of zero as a placeholder by Aryabhata. These rules travelled through Arabic scholars to Europe and underpin modern algebra. For UPSC they feature in GS-1 art and culture as standard evidence of India's contribution to mathematics and science.
Example: Brahmagupta's Brahmasphutasiddhanta, c. 628 CE.
Zero Hunger is Sustainable Development Goal 2, which commits the world to end hunger, achieve food security and improved nutrition, and promote sustainable agriculture by 2030. Its targets cover undernourishment, child stunting and wasting, and small farmer productivity. Progress is tracked by agencies like the FAO, and India cites it in debates on the National Food Security Act and nutrition missions. For UPSC it links food policy, agriculture, and human development.
Example: The World Food Programme won the 2020 Nobel Peace Prize for its work combating hunger, a core Zero Hunger mission.
Zero-based budgeting is a method in which every spending proposal must be justified afresh each budget cycle, starting from a base of zero instead of adjusting the previous year's allocations. It forces departments to defend each programme's existence and can expose wasteful legacy spending, though it is data-heavy and time-consuming to run. For UPSC it is relevant to GS-3 economy and GS-2 governance questions on public finance reform, expenditure rationalisation and outcome budgeting.
Example: President Jimmy Carter ordered United States federal agencies to prepare zero-based budgets in 1977.
Zero-Budget Natural Farming (ZBNF) is a low-cost farming method popularized by Subhash Palekar that rejects chemical fertilizers and pesticides, using cow dung, cow urine, mulching, and intercropping to cut input costs to near zero. Andhra Pradesh scaled it as a state program to raise farmer incomes and restore soil health. For UPSC, ZBNF anchors environment and agriculture answers on sustainable farming and the goal of raising farmer incomes.
Example: Subhash Palekar, champion of ZBNF
Zeugen is the German word for 'witnesses' (singular Zeuge); the verb zeugen means 'to bear witness' or 'to beget'. In UPSC reading it appears only in translated or German-derived material, such as discussions of testimony and witness protection, or in world history as Zeugen Jehovas, the Jehovah's Witnesses persecuted in Nazi Germany. Treat it as a vocabulary item for GS-1 world history or GS-2 polity contexts.
Zikr is the Sufi practice of rhythmic remembrance of God through the recitation of divine names and phrases, often performed aloud in congregation. Practiced across Sufi orders, it aims at spiritual purification and closeness to the divine. For UPSC, zikr illustrates the devotional core of Sufism in medieval Indian culture and its role in spreading Islam through personal piety rather than coercion.
Zil-i-illahi is a Persian phrase meaning the Shadow of God on earth, a title of divine kingship claimed by Delhi Sultans and Mughal rulers to sanctify their authority. Balban was its most emphatic claimant, insisting the Sultan stood above law and custom. For UPSC, it is key to understanding the theory of kingship in the Delhi Sultanate and Indo-Persian political thought.
Example: Ghiyasuddin Balban
Zil-i-illahi, the Shadow of God on earth, is the royal title by which Delhi Sultans and Mughal emperors claimed to rule as God's vicegerent, placing the monarch's authority beyond challenge. Balban used it most forcefully to sacralize his kingship and demand absolute obedience. For UPSC, it is the classic formulation of divine-right theory in the Sultanate and a mains-ready point on medieval statecraft.
Example: Ghiyasuddin Balban's theory of kingship
Zinc finger nucleases (ZFNs) are gene-editing tools made of engineered proteins that bind specific DNA triplets, fused to a DNA-cutting enzyme that cuts the genome at the bound site. They preceded CRISPR but are costlier and harder to design.
The Zollverein is the German customs union established in 1834 under Prussian leadership that abolished internal tariffs among most German states. By creating a single economic area with common external duties, it fostered industrial growth and railway building, making economic integration the forerunner of political unification under Prussia in 1871. For UPSC, it is the textbook case of economic nationalism preceding political nationhood.
Example: Its standardisation of weights, measures and currency across member states, which welded Germany into one market decades before one empire.
The Zollverein of 1834 is the customs union of German states under Prussian leadership that abolished internal tariffs and unified the market before political unification. It bound the lesser states economically to Prussia and excluded Austria; the economic template of the Empire.
Zonal Councils are statutory advisory bodies created under the States Reorganisation Act, 1956, dividing India into five zones for cooperation on matters of common interest such as economic planning, border disputes, and linguistic minorities. The Union Home Minister chairs each council. For UPSC, they are standard polity material on cooperative federalism and Centre-state relations.
Example: States Reorganisation Act, 1956
Zone IV is the second-highest seismic zone in India's earthquake zoning under BIS code IS 1893, denoting regions of high damage risk from earthquakes. The code divides the country into zones II to V based on expected intensity of shaking, guiding earthquake-resistant building design. For UPSC, seismic zoning links physical geography with disaster management and building-code policy.
Example: Delhi, Patna and much of the Indo-Gangetic plain lie in Zone IV, so their buildings must follow ductile detailing norms for earthquake resistance.
Zone V is the highest seismic zone in India's earthquake zoning under BIS code IS 1893, marking areas with the very highest risk of severe earthquake damage. Structures here must meet the strictest earthquake-resistant design standards. For UPSC, it connects plate-tectonic geography with disaster preparedness, insurance and infrastructure planning.
Example: The entire Northeast, Kutch in Gujarat, parts of Jammu and Kashmir and the Andaman and Nicobar Islands fall in Zone V, reflecting their position on active tectonic boundaries.
Zones III and II refer to India's seismic zones III and II under the Bureau of Indian Standards classification, denoting moderate and low earthquake damage risk respectively. Zone III covers about 30 percent of the country, including cities like Mumbai, Kolkata, and Chennai, while Zone II has minimal seismic activity. For UPSC, the zones matter for disaster management, building codes, and geography questions on earthquake preparedness.
Example: 1993 Latur earthquake in a Zone III region of Maharashtra
Zoonotic spillover is the transmission of a pathogen from animals to humans, the origin of most emerging infectious diseases including COVID-19, Nipah and avian flu.
Example: fruit bats are the reservoir from which Nipah virus spills over to humans
Zooxanthellae are single-celled photosynthetic dinoflagellate algae that live symbiotically inside the tissues of reef-building coral polyps, supplying the coral with energy from photosynthesis and giving reefs their colour. When stressed by warming seas, corals expel them, causing coral bleaching that can kill the reef if prolonged. For UPSC they are central to GS-3 environment questions on coral bleaching, ocean warming and marine biodiversity conservation.
Example: The mass bleaching events on Australia's Great Barrier Reef.
Zulfikar Ali Bhutto is the Pakistani leader who founded the Pakistan Peoples Party and served as President and then Prime Minister of Pakistan in the 1970s. He negotiated the 1972 Simla Agreement with Indira Gandhi and was executed in 1979 after Zia-ul-Haq's military coup. For UPSC, Bhutto is central to India-Pakistan relations, the aftermath of the Bangladesh war, and debates on nuclear proliferation.
Example: Simla Agreement, 1972
The Zunyi Conference is the January 1935 meeting during the Long March at which the Communist Party leadership shifted after early defeats, bringing Mao Zedong into effective command of the Red Army and the party.
ZyCoV-D is the world's first plasmid DNA vaccine approved for human use, developed by Ahmedabad-based Zydus Cadila with support from India's Department of Biotechnology and ICMR, receiving emergency use authorisation from the DCGI in August 2021. A circular piece of DNA encoding the coronavirus spike protein is delivered into skin cells, which then produce the spike protein and trigger an immune response; it is given in three doses on days 0, 28 and 56 via a painless needle-free intradermal injector. It was also the first COVID-19 vaccine authorised in India for adolescents aged 12 to 18.
Example: Because DNA vaccines are temperature-stable, ZyCoV-D demonstrated the plug-and-play DNA platform that can be adapted quickly to viral mutations.