disembogue v.

word-forming element of Latin origin meaning 1. "lack of, not" (as in dishonest); 2. "opposite of, do the opposite of" (as in disallow); 3. "apart, away" (as in discard), from Old French des- or directly from Latin dis- "apart, asunder, in a different direction, between," figuratively "not, un-," also "exceedingly, utterly." Assimilated as dif- before -f- and to di- before most voiced consonants.

The Latin prefix is from PIE *dis- "apart, asunder" (source also of Old English te-, Old Saxon ti-, Old High German ze-, German zer-). The PIE root is a secondary form of *dwis- and thus is related to Latin bis "twice" (originally *dvis) and to duo, on notion of "two ways, in twain" (hence "apart, asunder").

In classical Latin, dis- paralleled de- and had much the same meaning, but in Late Latin dis- came to be the favored form and this passed into Old French as des-, the form used for compound words formed in Old French, where it increasingly had a privative sense ("not"). In English, many of these words eventually were altered back to dis-, while in French many have been altered back to de-. The usual confusion prevails.

As a living prefix in English, it reverses or negatives what it is affixed to. Sometimes, as in Italian, it is reduced to s- (as in spend, splay, sport, sdain for disdain, and the surnames Spencer and Spence).

French, literally "mouth" (Old French boche, 11c.), from Latin bucca "cheek," which in Late Latin replaced os (see oral) as the word for "mouth" (and also is the source of Italian bocca, Spanish boca). De Vaan writes that "The meaning 'mouth' is secondary, and was originally used in a derogatory way." It is perhaps from Celtic, Germanic, or a non-IE substrate language.

The French word was borrowed in English in various senses, such as "king's allowance of food for his retinue" (mid-15c.); "mouth" (1580s); "metal plug for a cannon's vent" (1862; the verb in this sense is from 1781).