What does "ascertain" mean?
To find out definitely; to discover or establish.
Ascertain
/ˌæsəˈteɪn/ verb
verb ·Common ·High school level
Meaning at a glance
- Primary sense: To find out definitely; to discover or establish.
- Grammar: ascertain is listed as verb.
- Nearest alternatives: determine, afford proof of, analyze, appraise.
- Useful contrasts: guessing, assume, disbelieve.
- Usage evidence: We will first ascertain the cause of the disaster.
How to use "ascertain"
- Start with the primary definition, then check the part of speech before placing the word in a sentence.
- Compare nearby synonyms to make sure "ascertain" carries the exact meaning, tone, and strength you need.
- Use the example sentence as a context check. If your sentence uses the word differently, confirm that the grammar still fits.
Meaning check
- Does the word fit the sentence's grammar?
- Does it match the intended tone rather than only the dictionary definition?
- Would a simpler synonym be clearer for the reader?
- Is there enough surrounding context to prevent ambiguity?
Source and review context
This entry combines structured lexical data with WordToolSet review checks. Definitions, examples, synonyms, and usage notes may come from different source tables, so the page is designed to show evidence from more than one angle before you rely on "ascertain" in a final draft.
If a word has several senses, prefer the sense that matches your sentence's grammar and surrounding context. A correct definition can still be the wrong choice when the sentence needs a different register, emphasis, or level of specificity.
Before you rely on this definition
Read the first definition as a starting point, then check the example, synonyms, and part of speech before treating "ascertain" as the right word for your sentence.
If your draft is formal, technical, persuasive, or sensitive, compare "ascertain" with a nearby alternative so the final choice matches both meaning and reader expectation.
Compare nearby meanings
- Use synonyms when you need a softer, stronger, simpler, or more specific word.
- Use antonyms to check the boundary of the meaning and avoid accidental contrast.
- Use the example sentence to confirm the word behaves naturally in context.
- Keep the original wording when a replacement adds complexity without improving precision.
Definition decision workflow
1. Identify the role
Check whether "ascertain" is acting as verb in your sentence. A definition is only useful when the grammar matches the way the word is being used.
2. Test the nearest option
Compare it with "determine" and other nearby choices to see whether the sentence needs a softer, stronger, or more familiar word.
3. Confirm with context
Use the example sentence below as an evidence check, then read your own sentence out loud to catch tone or rhythm problems.
Review note: Definition pages are checked for source coverage, sentence evidence, synonym support, and editorial insight before they are treated as approval-ready pages. If the evidence is too thin, the page remains available to users but is kept out of the approval-facing indexed inventory.
Final meaning check
Before publishing a sentence with "ascertain", ask whether the word helps the reader understand the idea faster. A precise word should reduce confusion, not simply make the sentence look more polished.
When the definition, synonym evidence, and example context point in the same direction, the word is usually a safer choice. When they conflict, revise the sentence or choose a clearer alternative.
Definitions
Verb
- 1 To find out definitely; to discover or establish. transitive
"As soon as we ascertain what the situation is, we can plan how to proceed."
- 2 be careful or certain to do something; make certain of something wordnet
- 3 To make (someone) certain or confident about something; to inform. obsolete, transitive
"Therfore the saide cõmissioners shall mowe say that nowe late during the parlement the King ascertaigned of the saide maliciouse pʳpose of his enemys, willed and desired the lords being then present to shewe their̃ good willes aide and helpe for the saide rescues[…]"
- 4 learn or discover with certainty wordnet
- 5 To look for something lost. Yorkshire, dated, intransitive
Show 4 more definitions
- 6 establish after a calculation, investigation, experiment, survey, or study wordnet
- 7 To establish, to prove. archaic, transitive
"The two firſt lines of the following book ſeem to aſcertain the true meaning of the concluſion of this, and to prove ſufficiently that by Ωκεανός here, Homer could not poſſibly intend any other than a river."
- 8 find out, learn, or determine with certainty, usually by making an inquiry or other effort wordnet
- 9 To ensure or effect. archaic, transitive
"It is true, that no diligence can aſcertain ſucceſs ; death may intercept the ſwifteſt career ; but he who is cut off in the execution of an honeſt undertaking, has at leaſt the honour of falling in his rank, and has fought the battle, though he miſſed the victory."
Antonyms
Example
"We will first ascertain the cause of the disaster."
Common questions
What is a synonym for "ascertain"?
Common synonyms include: determine, afford proof of, analyze, appraise, ask, assure.
How do you use "ascertain" in a sentence?
We will first ascertain the cause of the disaster.
How do you pronounce "ascertain"?
Pronounced /ˌæsəˈteɪn/.
Etymology
From Middle English acerteynen, from Old French acertener, from a- (“to, towards”) + certener (“make sure of”), from the adjective certain, from Latin certus (“certain, fixed”). Compare to Spanish acertar.