ascertain
verb
as·cer·tain ˌa-sər-ˈtān 
ascertained; ascertaining; ascertains
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
ascertainable
ˌa-sər-ˈtā-nə-bəl
adjective ascertainment
ˌa-sər-ˈtān-mənt
noun 
Synonyms
- catch on (to)
- discover
- find out
- get on (to)
- hear
- learn
- realize
- see
- wise (up)
See all Synonyms & Antonyms 
Example Sentences
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
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 on the Web The stamp was part of an effort to create an international color-coding system that would allow postal workers in countries using different languages and currencies to ascertain that proper postage had been applied to each piece of mail. Chris Klimek, Smithsonian Magazine, 6 Sep. 2022 Ed O’Carroll said department officials still don’t know why the detectives accused Van Winkle of fabricating the assault, but said aggressive questioning was a tactic sometimes used at the time to try to ascertain if a victim was making up a story. Justin Jouvenal, Washington Post, 2 Aug. 2022 Officials have long pointed to at-home testing as a pivotal prong in the nation’s coronavirus response — allowing residents to ascertain and monitor their status and take appropriate precautions to avoid infecting others. Los Angeles Times, 25 Aug. 2022 Russell is one of more than a dozen Alabama residents charged in connection with Capitol breach during a joint session of Congress which had convened to ascertain and count the electoral votes related to the presidential election. Carol Robinson | Crobinson@al.com, al, 24 Aug. 2022 Scientists use multiple ways to ascertain Earth’s spinning speed, including evidence from shells. Manasee Wagh, Popular Mechanics, 16 Aug. 2022 In addition to utilizing a rubric or scorecard to ensure objectivity during the hiring process, candidates should be asked a series of questions to better ascertain their interest and commitment to racial equity. Janice Gassam Asare, Forbes, 11 Aug. 2022 Beijing’s censors never explain nor comment publicly on their decisions, but industry participants inside and outside of China scrutinize such moves carefully and backchannel with authorities to ascertain where the lines are drawn. Patrick Brzeski, The Hollywood Reporter, 10 July 2022 To ascertain whether hermit crabs experience pain, a pair of researchers at Queen’s University Belfast prodded them with electric shocks, and to figure out the same thing for squid a biologist at San Francisco State sliced them with scalpels. Elizabeth Kolbert, The New Yorker, 6 June 2022 See More
Chris Klimek, Smithsonian Magazine, 6 Sep. 2022 Ed O’Carroll said department officials still don’t know why the detectives accused Van Winkle of fabricating the assault, but said aggressive questioning was a tactic sometimes used at the time to try to ascertain if a victim was making up a story. Justin Jouvenal, Washington Post, 2 Aug. 2022 Officials have long pointed to at-home testing as a pivotal prong in the nation’s coronavirus response — allowing residents to ascertain and monitor their status and take appropriate precautions to avoid infecting others. Los Angeles Times, 25 Aug. 2022 Russell is one of more than a dozen Alabama residents charged in connection with Capitol breach during a joint session of Congress which had convened to ascertain and count the electoral votes related to the presidential election. Carol Robinson | Crobinson@al.com, al, 24 Aug. 2022 Scientists use multiple ways to ascertain Earth’s spinning speed, including evidence from shells. Manasee Wagh, Popular Mechanics, 16 Aug. 2022 In addition to utilizing a rubric or scorecard to ensure objectivity during the hiring process, candidates should be asked a series of questions to better ascertain their interest and commitment to racial equity. Janice Gassam Asare, Forbes, 11 Aug. 2022 Beijing’s censors never explain nor comment publicly on their decisions, but industry participants inside and outside of China scrutinize such moves carefully and backchannel with authorities to ascertain where the lines are drawn. Patrick Brzeski, The Hollywood Reporter, 10 July 2022 To ascertain whether hermit crabs experience pain, a pair of researchers at Queen’s University Belfast prodded them with electric shocks, and to figure out the same thing for squid a biologist at San Francisco State sliced them with scalpels. Elizabeth Kolbert, The New Yorker, 6 June 2022 See More Word History
Etymology
Middle English acertainen to inform, give assurance to, from Anglo-French acerteiner, from a- (from Latin ad-) + certein, certain certain
First Known Use
15th century, in the meaning defined at sense 2
Kids Definition
ascertain
verb
as·cer·tain ˌa-sər-ˈtān
ascertained; ascertaining
: to find out with certainty
Police tried to ascertain the cause of the accident.
ascertain
verb
1
as in to discover
to come to an awareness of was immediately able to ascertain that the girl was uncomfortable talking about her life at home Synonyms & Similar Words
Relevance
- discover
- realize
- see
- hear
- learn
- find
- find out
- detect
- get on (to)
- catch on (to)
- discern
- descry
- espy
- get wind of
- perceive
- spot
- calculate
- figure out
- encounter
- observe
- wise (up)
- divine
- tumble (to)
- note
- hit (on or upon)
- puzzle (out)
- mind
- dope (out)
Antonyms & Near Antonyms
- miss
- ignore
- overlook
- disregard
- forget
- conceal
- hide
- cover
- curtain
- mask
- veil
- unlearn
- screen
- blot out
- cloak
- enshroud
- occult
- blanket
- shroud
2
as in to find
to come upon after searching, study, or effort ascertained that their old colonial-era house had once functioned as a tavern Synonyms & Similar Words
- find
- discover
- learn
- locate
- determine
- get
- detect
- descry
- find out
- dig up
- dig out
- run down
- rummage
- turn up
- scare up
- nose out
- spot
- sight
- track (down)
- espy
- scout (up)
- hunt (down or up)
- dredge (up)
- hit (on or upon)
- seek
- ferret (out)
- rout (out)
- root (out)
- look for
- search (for or out)
Antonyms & Near Antonyms
- overlook
- miss
- pass over
- mislay
- lose
- misplace
- misset
Synonym Chooser
Some common synonyms of ascertain are determine, discover, learn, and unearth. While all these words mean "to find out what one did not previously know," ascertain implies effort to find the facts or the truth proceeding from awareness of ignorance or uncertainty.
attempts to ascertain the population of the region
The meanings of determine and ascertain largely overlap; however, determine emphasizes the intent to establish the facts definitely or precisely.
unable to determine the origin of the word
While in some cases nearly identical to ascertain, discover may apply to something requiring exploration or investigation or to a chance encounter.
discovered the source of the river
The words learn and ascertain can be used in similar contexts, but learn may imply acquiring knowledge with little effort or conscious intention (as by simply being told) or it may imply study and practice.
I learned her name only today
learning Greek
The words unearth and ascertain are synonyms, but do differ in nuance. Specifically, unearth implies bringing to light something forgotten or hidden.
unearth old records
- cabin cruisers
- cabin fever
- cabin hook
- cabin house
- cabin passenger
- cabin supercharger
- Cabinda
- cabined
- cabineer
- cabinet
- cabinet ball
- cabinet beetle
- cabinet bench
- cabinet cherry
- cabinet council
- cabinet file
- merismoid
- meristele
- meristelic
- meristem
- meristematic
- meristematically
- meristems
- meristic
- meristically