The Collaborative International Dictionary of English v.0.48:
Ascertain \As`cer*tain"\, v. t. [imp. & p. p. Ascertained; p.
pr. & vb. n. Ascertaining.] [OF. acertener; a (L. ad) +
certain. See Certain.]
1. To render (a person) certain; to cause to feel certain; to
make confident; to assure; to apprise. [Obs.]
When the blessed Virgin was so ascertained. --Jer.
Muncer assured them that the design was approved of
by Heaven, and that the Almighty had in a dream
ascertained him of its effects. --Robertson.
2. To make (a thing) certain to the mind; to free from
obscurity, doubt, or change; to make sure of; to fix; to
The divine law . . . ascertaineth the truth.
The very deferring [of his execution] shall increase
and ascertain the condemnation. --Jer. Taylor.
The ministry, in order to ascertain a majority . . .
persuaded the queen to create twelve new peers.
The mildness and precision of their laws ascertained
the rule and measure of taxation. --Gibbon.
3. To find out or learn for a certainty, by trial,
examination, or experiment; to get to know; as, to
ascertain the weight of a commodity, or the purity of a
He was there only for the purpose of ascertaining
whether a descent on England was practicable.