Either of two people (or, less commonly, animals) who shared the same uterus at the same time; one who was born at the same birth as a sibling.

(transitive, obsolete outside Scotland) To separate, divide. / (intransitive, obsolete outside Scotland) To split, part; to go away, depart.

Double; dual; occurring as a matching pair. / Forming a pair of twins.

present participle of twin

action of the verb to twin / giving birth to twins / the pairing of similar objects (such as towns) / (crystallography) the formation of twin crystals

biparous

plural of twin

(slang) A woman's breasts.

Third-person singular simple present indicative form of twin

plural of twinning