ascertain

[ as-er-teyn ]

/ ˌæs ərˈteɪn /

SEE MORE SYNONYMS FOR ascertain 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.

RELATED WORDS

Nearby words

Origin of ascertain

1400–50; late Middle English, variant of assertain, acertain < Middle French acertain- (tonic stem of acertener to make certain), equivalent to a- a-⁵ + certain certain

Related forms

as·cer·tain·a·ble, adjectiveas·cer·tain·a·bly, adverbas·cer·tain·er, nounas·cer·tain·ment, noun

non·as·cer·tain·a·ble, adjectivenon·as·cer·tain·a·ble·ness, nounnon·as·cer·tain·a·bly, adverbnon·as·cer·tain·ment, nounpre·as·cer·tain, verb (used with object)pre·as·cer·tain·ment, nounun·as·cer·tain·a·ble, adjectiveun·as·cer·tain·a·bly, adverbun·as·cer·tained, adjectivewell-as·cer·tained, adjective

Synonym study

1. See learn.

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for ascertainable

But all these are facts of nature, belonging to the case, ascertainable by experience and reason.
A Defence of Virginia|Robert L. Dabney
Descent would necessarily be traced through females, because the paternity of children was not ascertainable with certainty.
Ancient Society|Lewis Henry Morgan
The only ascertainable fact is that he was the proprietor of the house with the sign of the Bear (l'Ours).
The Life of Joan of Arc, Vol. 1 and 2 (of 2)|Anatole France
As for the elasticity of the ether, that is ascertainable at once from the speed at which it transmits waves.
The Ether of Space|Oliver Lodge

Sexual selection, even when left to random influences, is still not left to chance; it follows definite and ascertainable laws.
The Task of Social Hygiene|Havelock Ellis

British Dictionary definitions for ascertainable

ascertain

/ (ˌæsəˈteɪn) /

verb (tr)

to determine or discover definitely

archaic to make certain

Derived Formsascertainable, adjectiveascertainably, adverbascertainment, noun

Word Origin for ascertain

C15: from Old French acertener to make certain

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

Word Origin and History for ascertainable (1 of 2)

ascertainable

adj.

1783, from ascertain + -able. Related: Ascertainably.

Word Origin and History for ascertainable (1 of 2)

ascertain

early 15c., "to inform, to give assurance," from Anglo-French acerteiner, Old French acertener "to assure, certify" (13c.), from a "to" (see ad-) + certain "certain" (see certain). Modern meaning of "find out for sure by experiment or investigation" is first attested 1794. Related: Ascertained; ascertaining.