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 twinning

simple past tense and past participle of twin

Produced at, or as if at, a single birth; united.

The state, quality, or condition of a twin; twinship.

A complication of disproportionate blood supply between unborn twins, resulting in high morbidity and mortality.

(baseball, slang) A double play.

(crystallography) either of two separate crystals that share crystal lattice points in a symmetrical manner and intergrow

(of an aircraft) powered by two engines, one in each wing