|asə(r)|tān, ˌaas- transitive verb
( -ed/-ing/-s )
Etymology: Middle English acertainen, from Middle French acertainer, acertener, from Old French acertener, from a- (from Latin ad- ) + -certener (from certain ) — more at certain
1.
a. obsolete : to make (a person) certain, sure, or confident : assure
but how shall I be ascertained that I also shall be entertained — John Bunyan
b. archaic : to make (a thing) certain : establish as a certainty : determine with certainty
but who shall exactly ascertain to us what superstition is — George Horne †1792
c. obsolete : to make certain the possession of : secure
no diligence can ascertain success — Samuel Johnson
d. obsolete : to bring or deliver (a person) certainly : destine
would ascertain us into a possession of all the promises — Jeremy Taylor
e. archaic : to make (a thing) certain, exact, or precise : settle , fix
some effectual method for correcting, enlarging, and ascertaining our language — Jonathan Swift
2. : to find out or learn for a certainty (as by examination or investigation) : make sure of : discover
a sensitive instrument for ascertaining the people's ideas and wishes — A.R.Williams
had ascertained … that his son-in-law was among the living prisoners — Charles Dickens
Synonyms: see discover