wholesale (adj.)

Old English hal "entire, whole; unhurt, uninjured, safe; healthy, sound; genuine, straightforward," from Proto-Germanic *haila- "undamaged" (source also of Old Saxon hel, Old Norse heill, Old Frisian hal, Middle Dutch hiel, Dutch heel, Old High German, German heil "salvation, welfare"), from PIE *kailo- "whole, uninjured, of good omen" (source also of Old Church Slavonic celu "whole, complete;" see health).

The spelling with wh- developed early 15c. The sense in whole number is from early 14c. Whole milk is from 1782. On the whole "considering all facts or circumstances" is from 1690s. For phrase whole hog, see hog (n.).

Middle English sale, from late Old English sala "a sale, act of selling," which according to OED probably is from a Scandinavian source such as Old Norse sala "sale," but in either case from Proto-Germanic *salo (source also of Old High German sala, Swedish salu, Danish salg), from PIE root *sal- (3) "to grasp, take."

The specific application to a public auction is by 1670s. The sense of "a selling of shop goods at lower prices than usual" is attested by 1866. To be for sale "available for purchase, intended to be sold" is by 1610s; on sale in the same sense is by 1540s; the earlier form was to sale (late 14c.). Salariat "the salaried class" is by 1918, from French. Also see sales.

early 15c., "sale of commodities in small quantities or parcels" (opposed to wholesale), from Old French retail "piece cut off, shred, scrap, paring" (Modern French retaille), from retaillier "cut back, cut off" (see retail (v.)). The notion of the English word is "a selling by the piece." This sense is not in French, however, and comes perhaps from cognate Italian ritaglio, which does have that sense. As an adjective, "of or pertaining to sale at retail," c. 1600.