Not being a professional grammarian or linguist, I don't want to add it myself, but: I have heard on many occasions the term "twinning" for an adjective(?) describing an animal producing two offspring (i.e., twins) at a time, or having a tendency to do so. I figured I'd leave a comment so someone more educated than myself could add it if they feel it is appropriate. Here is an example: Twinning is very common among Icelandic sheep. Isoxyl 19:54, 7 February 2006 (UTC)
Probably a british slang term? Or, Cockney rhyming slang? {{subst:UnsignedIP|87.116.147.151|16:12, 2 September 2007 (UTC)}}
Is twin possibly derived from the same root meaning as twain? The forms seem to have similar meanings and sounds as well. (Old English ġetwinn for twin and Proto-Germanic *dwó for twain). But there is no etymology past ġetwinn for twin, so I wouldn't know. - M0rphzone (talk) 23:33, 23 April 2012 (UTC)