Twin (?), a. [OE. twin double, AS. getwinne two and two, pl., twins;
akin to D. tweeling a twin, G. zwilling, OHG. zwiniling, Icel. tvennr,
tvinnr, two and two, twin, and to AS. twi- two. See Twice, Two.] 1.
Being one of two born at a birth; as, a twin brother or sister.
2. Being one of a pair much resembling one another; standing the
relation of a twin to something else; — often followed by to or with.
Shak.