To discover with certainty, as through examination or experimentation. See Synonyms at discover.(verb-transitive)
Archaic To make certain, definite, and precise.(verb-transitive)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "ascertain" in a sentence
"I was able to ascertain from the News forum that there's at least one Telcel shop in Alamos."
"Separate and distinct from all the preceding categories of signing statement, and apparently even more controversial than any of them, is the use of such statements to create legislative (or "executive") history that is expected to be given weight by the courts in ascertain the meaning of statutory language."
"This we can ascertain from the frames in Scene 3, where UN troops are present."