an·​te·​di·​lu·​vi·​an | \ˌan-ti-də-ˈlü-vē-ən, -(ˌ)dī-\

Definition of antediluvian 

1 : of or relating to the period before the flood described in the Bible

2a : made, evolved, or developed a long time ago an antediluvian automobile that antediluvian relic known as a slide rule

b : extremely primitive or outmoded an antediluvian prejudice antediluvian in his politics

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Other Words from antediluvian

antediluvian noun

Synonyms & Antonyms for antediluvian


age-old, aged, ancient, antique, dateless, hoar, hoary, immemorial, old, venerable


modern, new, recent

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Did You Know?

Before there was "antediluvian," there were the Latin words ante (meaning "before") and "diluvium" (meaning "flood"). As long ago as 1646, English speakers were using "antediluvian" to describe conditions they believed existed before the great flood described in the biblical account of Noah and the ark. By the early 1700s, the word had come to be used as both an adjective and a noun referring to anything or anyone prodigiously old. Charles Darwin used it to characterize the mighty "antediluvian trees" some prehistoric mammals might have used as a food source, and in his American Notes, Charles Dickens described an elderly lady who informed him, "It is an extremely proud and pleasant thing . . . to be an antediluvian."

Examples of antediluvian in a Sentence

He has antediluvian notions about the role of women in the workplace. found evidence in the Middle East of an antediluvian people previously unknown to history

Recent Examples on the Web

The system now faces the antediluvian economics of President Donald Trump, who seems bent on its destruction. The Economist, "In America, a political coalition in favour of protectionism may be emerging," 15 Mar. 2018 The main difference is that whereas Trump hails from the nativist right, Corbyn descends from the antediluvian left. James Kirchick, Slate Magazine, "Don’t Give Corbyn a Pass," 22 Aug. 2017 Yet out of this stew of sadism, closeted homosexuality and antediluvian notions of machismo came some great art. Scott Stossel, WSJ, "Review: ‘Wayne and Ford,’ Co-creating Masculinity," 15 Dec. 2017 In order to win the battle on this issue, the administration will have to get free of the antediluvian tyranny of the Congressional Budget Office, which has not predicted any economic development accurately in decades. Conrad Black, National Review, "Las Vegas, the NFL, and Jimmy Kimmel," 5 Oct. 2017 Although the Lot Radio lies within spitting distance of Williamsburg’s looming hotels and overflowing nightclubs, this makeshift hangout, which began as an internet radio station and coffee shop, conjures a charmingly antediluvian era. Ben Detrick, New York Times, "A Makeshift Bar on a Dusty Brooklyn Patch," 9 May 2017 In addition, China’s antediluvian and fragmented grid system prioritizes power plants nearby urban centers, with normally far-flung solar and wind farms typically used just to top up., "The world’s largest floating solar farm," 18 July 2017 But at least you weren’t sandbagged by some antediluvian notion of how family is supposed to work. John Anderson, New York Times, "Films Like ‘The Boss Baby’ Can Be Painful for Adoptees and Foster Kids," 5 Apr. 2017 Some of the earliest restorations of dinosaurs and marine reptiles by the 19th century artist John Martin were apocalyptic spectacles of antediluvian combat where scavengers waited to pick at the remains of the losing contestant. Brian Switek, WIRED, "Toumai and the Sabercats," 20 Jan. 2011

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'antediluvian.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of antediluvian

1646, in the meaning defined at sense 1

History and Etymology for antediluvian

ante- + Latin diluvium flood — more at deluge

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The first known use of antediluvian was in 1646

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English Language Learners Definition of antediluvian

: very old or old-fashioned

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playful or foolish behavior

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