n. A trial or special observation, made to confirm or disprove something uncertain; esp., one under controlled conditions determined by the experimenter; an act or operation undertaken in order to discover some unknown principle or effect, or to test, establish, or illustrate some hypothesis, theory, or known truth; practical test; proof.n. Experience.v. To make experiment; to operate by test or trial; -- often with on, upon, or in, referring to the subject of an experiment; with, referring to the instrument; and by, referring to the meansv. To try; to know, perceive, or prove, by trial or experience.