Chloroform \Chlo"ro*form\, n. [Chlorine + formyl, it having been regarded as a trichloride of this radical: cf. F. chloroforme, G. chloroform.] (Chem.) A colorless volatile liquid, {CHCl3}, having an ethereal odor and a sweetish taste, formed by treating alcohol with chlorine and an alkali. It is a powerful solvent of wax, resin, etc., and is extensively used to produce an[ae]sthesia in surgical operations; also externally, to alleviate pain.