1. (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.

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