Origin and history of decant

"slope, slant," late 14c., first in Scottish writing and apparently meaning "edge, brink," a word of uncertain origin. "[W]ords identical in form and corresponding in sense are found in many languages, Teutonic, Slavonic, Romanic, Celtic" [OED, 1989]. It was rare in English before c. 1600. The meaning "slope, slanting or tilting position" is from 1847.

Perhaps it comes via Old North French cant "corner" (itself perhaps via Middle Low German kante or Middle Dutch kant), from Vulgar Latin *canthus, from Latin cantus "iron tire of a wheel," which is possibly from a Celtic word meaning "rim of wheel, edge, brim" (compare Welsh cant "bordering of a circle, tire, edge," Breton cant "circle"). The ultimate connections of these are uncertain. Greek kanthos "corner of the eye," and Russian kutu "corner" sometimes are suggested, but there are difficulties (see Beekes).

vessel for decanting liquors, 1715, agent noun from decant.

active word-forming element in English and in many verbs inherited from French and Latin, from Latin de "down, down from, from, off; concerning" (see de), also used as a prefix in Latin, usually meaning "down, off, away, from among, down from," but also "down to the bottom, totally" hence "completely" (intensive or completive), which is its sense in many English words.

As a Latin prefix it also had the function of undoing or reversing a verb's action, and hence it came to be used as a pure privative — "not, do the opposite of, undo" — which is its primary function as a living prefix in English, as in defrost (1895), defuse (1943), de-escalate (1964), etc. In some cases, a reduced form of dis-.