disengage (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).

early 15c., "to pledge" (something, as security for payment), from Old French engagier "bind (by promise or oath), pledge; pawn" (12c.), from phrase en gage "under pledge," from en "in" (see en- (1)) + gage "pledge," through Frankish from Proto-Germanic *wadiare "pledge" (see wed). It shows the common evolution of Germanic -w- to central French -g- (see gu-).

Meaning "attract and occupy the attention of" is from 1640s; that of "employ, secure for aid, employment or use" is from 1640s, from notion of "binding as by a pledge;" meaning "enter into combat or contest with" is from 1640s. Specific sense of "promise to marry" is 1610s (implied in engaged). Machinery sense is from 1884. Also from the French word are German engagiren, Dutch engageren, Danish engagere.

1640s, "act or process of setting free; state of being disengaged," from French désengagement, from desengager (see disengage). By 1701 as "freedom from engrossing occupation, leisure."