being one of two born at a birth; as, a twin brother or sister.-being one of a pair much resembling one another; standing the relation of a twin to something else; -- often followed by to or with.-double; consisting of two similar and corresponding parts.-composed of parts united according to some definite law of twinning. see twin, n., 4.-one of two produced at a birth, especially by an animal that ordinarily brings forth but one at a birth; -- used chiefly in the plural, and applied to the young of beasts as well as to human young.-a sign and constellation of the zodiac; gemini. see gemini.-a person or thing that closely resembles another.-a compound crystal composed of two or more crystals, or parts of crystals, in reversed position with reference to each other.-to bring forth twins.-to be born at the same birth.-to cause to be twins, or like twins in any way.-to separate into two parts; to part; to divide; hence, to remove; also, to strip; to rob.-to depart from a place or thing.