Twain \Twain\, a. & n. [OE. twein, tweien, tweyne, AS. tw[=e]gen, masc. See Two.]

Two; -- nearly obsolete in common discourse, but used in poetry and burlesque. ``Children twain.'' --Chaucer.

And whosoever shall compel thee to go a mile, go with him twain. --Matt. v. 41.

In twain, in halves; into two parts; asunder.

When old winder split the rocks in twain. --Dryden.

Twain cloud. (Meteor.) Same as Cumulo-stratus.

Source: Webster's Revised Unabridged Dictionary (1913)