ascertain

verb as·cer·tain \ ˌa-sər-ˈtān \

Updated on: 10 May 2018

Definition of ascertain

transitive verb

1 : to find out or learn with certainty

ascertain the truth

trying to ascertain the cause of the fire

information that can be easily ascertained on the Internet

2 archaic : to make certain, exact, or precise

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ascertainable

play \-ˈtā-nə-bəl\ adjective

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ascertainment

play \-ˈtān-mənt\ noun

See ascertain defined for English-language learners

See ascertain defined for kids

Examples of ascertain in a Sentence

We look at digital media—images, audio and video—and we try to ascertain whether or not they've been manipulated. We use mathematical and computational techniques to detect alterations in them. —Claudia Dreifus, New York Times, 2 Oct. 2007
Currently, an official trying to ascertain road damage in the aftermath of an earthquake might have to keep one eye on the TV news while listening to both radio traffic reports and the police scanner. Since most of these data are available in digital form, the software could take them all in, process them and present a report outlining the best evacuation routes. —Kevin Hogan, Technology Review, April 2002
With an equation linking the money wage to prices, the degree of inflation could be ascertained. —Sidney Weintraub, Modern Economic Thought, (1977) 1993

Recent Examples of ascertain from the Web

Whether dog owners truly are more empathetic and nurturing than those who don’t own pets is harder to ascertain.

— roni caryn rabin, New York Times, "Need a Date? First, Get a Dog," 27 Feb. 2018
Such incidents are not uncommon and underscore the difficulty of ascertaining from an image on a TV monitor exactly what's happening on the ground.

— sharon weinberger, Popular Mechanics, "How ESPN Taught the Pentagon to Handle a Deluge of Drone Data," 11 June 2012
Whether or not this message resonates with black communities is hard to ascertain.

— astead w. herndon, BostonGlobe.com, "Threatened by youth movement, NRA exploits racial divisions," 29 Mar. 2018
From the very first episode, O’Neill and Schmidt are at each other’s throats for reasons that are hard to ascertain.

— sophie gilbert, The Atlantic, "The Gripping History of The Looming Tower," 1 Mar. 2018
The processors do properly block the write, but the speculative execution minutely disturbs the processor state, because certain data will be loaded into cache and the TLB in order to ascertain whether the write should be allowed.

— peter bright, Ars Technica, "What’s behind the Intel design flaw forcing numerous patches?," 3 Jan. 2018
When her name could not be found on the rolls, polling place workers kindly walked her through the process of casting a provisional ballot until her eligibility to vote could be ascertained at a later date.

— jay willis, GQ, "Voter Fraud Is a Racist Lie," 30 Mar. 2018
Twitter, social media, and the court of public opinion are not the best means to ascertain and establish the truth.

— justin barrasso, SI.com, "Week in Wrestling: The Story Behind Roman Reigns' Promo on Brock Lesnar; Ross Report Returning Soon," 28 Feb. 2018
While The Bee did not ascertain if the student had access to other materials, another HISP student involved in the science fair said the project was assigned last fall and students have been working on it since.

— anita chabria and diana lambert, sacbee, "Here are some answers about the ‘Race and IQ’ science project that caused an uproar," 13 Feb. 2018

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

Origin and Etymology of ascertain

Middle English acertainen to inform, give assurance to, from Anglo-French acerteiner, from a- (from Latin ad-) + certein, certain certain

NEW! Time Traveler

First Known Use: 15th century

in the meaning defined at sense 2

See Words from the same year

ascertain Synonyms

Synonym Discussion of ascertain

discover, ascertain, determine, unearth, learn mean to find out what one did not previously know. discover may apply to something requiring exploration or investigation or to a chance encounter.