Origin of twainMiddle English twene ; from Old English twegen, nominative and amp; accusative masculine form of twa, two
Origin of Twain; from Mark twain!, two fathoms! (twelve feet of depth in the water), river pilot's cry indicating it is safe to proceed
Origin of twainMiddle English tweien, twaine, from Old English twēgen; see dwo- in Indo-European roots.
The word outlasted the breakdown of gender in Middle English and survived as a secondary form of two, then especially in the cases where the numeral follows a noun. Its continuation into modern times was aided by its use in KJV, the Marriage Service, in poetry (where it's commonly used as a rhyme word), and in oral use where it is necessary to be clear that two and not "to" or "too" is meant.
It could look like one of the many English words inherited from Old Norse. The modern Danish word is "tvende" (pronounced tvenne), it means both, two of a kind, etc.
- A surname.
twain - Computer Definition
(Technology Without An Interesting Name) A programming interface that lets a graphics application, such as an image editing program or desktop publishing program, activate a scanner, frame grabber or other image-capturing device.