Twin1. (a.) Being one of two born at a birth; as, a twin brother or sister.
2. (a.) Being one of a pair much resembling one another; standing the relation of a twin to something else; -- often followed by to or with.
3. (a.) Double; consisting of two similar and corresponding parts.
4. (a.) Composed of parts united according to some definite law of twinning. See Twin, n., 4.
5. (n.) 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.
6. (n.) A sign and constellation of the zodiac; Gemini. See Gemini.
7. (n.) A person or thing that closely resembles another.
8. (n.) A compound crystal composed of two or more crystals, or parts of crystals, in reversed position with reference to each other.
9. (v. i.) To bring forth twins.
10. (v. i.) To be born at the same birth.
11. (v. t.) To cause to be twins, or like twins in any way.
12. (v. t.) To separate into two parts; to part; to divide; hence, to remove; also, to strip; to rob.
13. (v. i.) To depart from a place or thing.
Thesaurus Entries
Doppelganger, Janus-like, accessory, accompanying, actual thing, alike, all one, all the same, ally, alter ego, ambidextrous, analogon, analogous, analogue, associate, associated, attendant, attending, bifacial, bifold, biform, bifurcated, bilateral, binary, binate, biparous, bipartisan, bipartite, bivalent, brother, carbon copy, clone, close copy, close match, coequal, cognate, coincident, collateral, combine, combined, companion, comparable, compeer, complement, concomitant, concurrent, conduplicate, congenator, congener, conjoint, connect, consubstantial, coordinate, copy, correlate, correlative, correspondent, corresponding, counterpart, couple, coupled, dead ringer, dichotomous, disomatous, ditto, double, double-faced, duadic, dual, dualistic, dupe, duple, duplex, duplicate, duplicated, dyadic, effigy, equal, equipollent, equivalent, exact counterpart, exact likeness, exactly alike, facsimile, fellow, geminate, geminated, homograph, homonym, homoousian, homophone, icon, idem, identic, identical, identical same, idol, image, indistinguishable, ingeminate, join, joined, joint, just alike, kindred spirit, like, likeness, link, living image, living picture, match, matched, matching, mate, miniature, mirroring, model, multiply by two, mutual, near duplicate, no other, none other, obverse, of a kind, of a piece, of a size, one, opposite number, pair, paired, parallel, paralleling, peer, pendant, photograph, picture, portrait, reciprocal, redouble, reduplicate, reflection, repeat, replica, replicate, reproduce, resemblance, ringer, rival, rubbing, same, second, second self, secondary, selfsame, semblance, shadow, similar, similitude, simulacrum, simultaneous, sister, soul mate, spit and image, spitting image, such, suchlike, synonym, tally, the like of, the likes of, the same, the same difference, trace, tracing, twain, twinned, two, two-faced, two-level, two-ply, two-sided, two-story, twofold, undifferent, very image, very picture, very same, without difference, without distinction, yoke