definition of
ascertain

[1] #1 ascertain v. [determine, find, find out] establish after a calculation, investigation, experiment, survey, or study; "find the product of two numbers"; "The physicist who found the elusive particle won the Nobel Prize". wn

[2] #2 ascertain v. [see, check, insure, see to it, ensure, control, assure] be careful or certain to do something; make certain of something; "He verified that the valves were closed"; "See that the curtains are closed"; "control the quality of the product". wn

[3] #3 ascertain v. [determine, check, find out, see, watch, learn] find out, learn, or determine with certainty, usually by making an inquiry or other effort; "I want to see whether she speaks French"; "See whether it works"; "find out if he speaks Russian"; "Check whether the train leaves on time". wn

[4] #4 ascertain v. learn or discover with certainty. wn