transitive verb. To discover with certainty, as through examination or experimentation. synonym: discover.

transitive verb. To make certain, definite, and precise.

To make certain; determine; define or reduce to precision by removing doubt, obscurity, or ambiguity; establish; prove.

To find out by trial, examination, or experiment, so as to know as certain; acquire an accurate knowledge of: as, to ascertain the weight of a commodity or the purity of a metal.

To make sure of; insure.

To make certain or sure; certify; assure; inform.

To establish with certainty; render invariable, or not subject to caprice; fix.

transitive verb. To render (a person) certain; to cause to feel certain; to make confident; to assure; to apprise.

transitive verb. To make (a thing) certain to the mind; to free from obscurity, doubt, or change; to make sure of; to fix; to determine.

transitive verb. To find out or learn for a certainty, by trial, examination, or experiment; to get to know.

verb. To find out definitely; to discover or establish.

verb. find out, learn, or determine with certainty, usually by making an inquiry or other effort

verb. establish after a calculation, investigation, experiment, survey, or study

verb. be careful or certain to do something; make certain of something

verb. learn or discover with certainty