ascertain

[ as-er-teyn ]

See synonyms for: ascertain ascertained ascertaining ascertainable on Thesaurus.com

verb (used with object)

to find out definitely; learn with certainty or assurance; determine: to ascertain the facts.
Archaic. to make certain, clear, or definitely known.

Origin of ascertain

First recorded in 1400–50; late Middle English, variant of acertain, assertain, from Middle French acertain-, stem of acertener “to make certain”; equivalent to a-⁵ + certain

Other words from ascertain

as·cer·tain·a·ble, adjective
as·cer·tain·a·bly, adverb
as·cer·tain·er, noun
as·cer·tain·ment, noun
non·as·cer·tain·a·ble, adjective
non·as·cer·tain·a·ble·ness, noun
non·as·cer·tain·a·bly, adverb
non·as·cer·tain·ment, noun
pre·as·cer·tain, verb (used with object)
pre·as·cer·tain·ment, noun
un·as·cer·tain·a·ble, adjective
un·as·cer·tain·a·bly, adverb
un·as·cer·tained, adjective
well-as·cer·tained, adjective

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use ascertain in a sentence

Previous Gaia data sets have been used to ascertain the mass of the Milky Way and how many sun-like stars might be orbited by Earth-light planets.
This is the most precise 3D map of the Milky Way ever made | Neel Patel | December 3, 2020 | MIT Technology Review
A discrete glance to ascertain all’s well is the better check-in stance.
At Moon Rabbit, chef Kevin Tien lures fans to the Wharf | Tom Sietsema | November 20, 2020 | Washington Post
I parked and inspected the damage, still trying to ascertain the cause.
I Hit a Cyclist with My Car | Brooke Warren | October 28, 2020 | Outside Online
This is especially true for online video where the lack of text makes it harder to ascertain the riskiness of the content.
As YouTube adopts new standards, the transition from brand safety to suitability is accelerating | Seb Joseph | October 22, 2020 | Digiday
Chief business officer Jeremi Gordon said it was “difficult to ascertain exactly what the impact of the Facebook boycott” might have had on Snap’s revenue.
How the world’s biggest media companies fared through the ongoing crisis in Q2 | Lara O'Reilly | August 12, 2020 | Digiday

"This is hours old and the full facts are still to be ascertained as those involved are debriefed," officials said.
Day 2: Breaking News About Osama bin Laden's Death | The Daily Beast | May 3, 2011 | THE DAILY BEAST
Rich natives and Chinese lost large sums of money, the total of which cannot be ascertained.
The Philippine Islands | John Foreman
The intention to hinder, delay or defraud creditors is a question of fact to be ascertained by proper judicial inquiry.
Putnam's Handy Law Book for the Layman | Albert Sidney Bolles
As soon as he had reached the south gate he had ascertained this by a glance at the gravel shoulder of the road.
Hooded Detective, Volume III No. 2, January, 1942 | Various
There are in fact no experiments in which the effects of a purely mineral soil have been ascertained.
Elements of Agricultural Chemistry | Thomas Anderson
When the question comes before a court, it seeks after the intention of the parties, and is guided by it when ascertained.
Putnam's Handy Law Book for the Layman | Albert Sidney Bolles

British Dictionary definitions for ascertain

ascertain

/ (ˌæsəˈteɪn) /

verb(tr)

to determine or discover definitely
archaic to make certain

Origin of ascertain

C15: from Old French acertener to make certain

Derived forms of ascertain

ascertainable, adjective
ascertainably, adverb
ascertainment, noun

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

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