- twin (adj.)
- Old English twinn "consisting of two, twofold, double, two-by-two," from Proto-Germanic *twisnjaz "double" (source also of Old Norse tvinnr "double, twin," Old Danish tvinling, Dutch tweeling, German zwillung), from PIE *dwisno- (source also of Latin bini "two each," Lithuanian dvynu "twins"), from *dwi- "double," from root *dwo- "two" (see two). Minneapolis and St. Paul in Minnesota have been the Twin Cities since 1883, but the phrase was used earlier of Rock Island and Davenport (1856).
- twin (v.)
- "to combine two things closely, join, couple," late 14c., from twin (adj.). Related: Twinned; twinning. In Middle English, the verb earlier and typically meant "to part, part with, separate from, estrange," etc. (c. 1200), on the notion of making two what was one.
- twin (n.)
- c. 1300, from Old English getwinn "double;" getwinnas "twins, two born at one birth," from twinn (see twin (adj.)).
