also over-sell, 1879, "sell more than one can deliver," from over- + sell (v.). Figurative sense of "make unrealistic or excessive claims for" is by 1928.
Entries linking to oversell
over-
word-forming element meaning variously "above; highest; across; higher in power or authority; too much; above normal; outer; beyond in time, too long," from Old English ofer (from PIE root *uper "over"). Over and its Germanic relations were widely used as prefixes, and sometimes could be used with negative force. This is rare in Modern English, but compare Gothic ufarmunnon "to forget," ufar-swaran "to swear falsely;" Old English ofercræft "fraud."
In some of its uses, moreover, over is a movable element, which can be prefixed at will to almost any verb or adjective of suitable sense, as freely as an adjective can be placed before a substantive or an adverb before an adjective. [OED]
Among the old words not now existing are Old English oferlufu (Middle English oferlufe), literally "over-love," hence "excessive or immoderate love." Over- in Middle English also could carry a sense of "too little, below normal," as in over-lyght "of too little weight" (c. 1400), overlitel "too small" (mid-14c.), oversmall (mid-13c.), overshort, etc.
sell v.
Middle English sellen, from Old English sellan "to give (something to someone), furnish, supply, lend; surrender, give up; deliver to; promise," from Proto-Germanic *saljanan "offer up, deliver" (source also of Old Norse selja "to hand over, deliver, sell;" Old Frisian sella, Old High German sellen "to give, hand over, sell;" Gothic saljan "to offer a sacrifice"), ultimately from PIE root *sel- (3) "to take, grasp."
Meaning "to give up for money, accept a price or reward for" had emerged by late Old English, but in Chaucer selle still can mean "to give." Students of Old English learn early that the word they encounter that looks like sell usually means "give." An Old English word for "to sell" was bebycgan, from bycgan "to buy."
The meaning "betray for gain" is from c. 1200. Slang meaning "to swindle" is from 1590s. To sell off "dispose of by sale, sell all of" is by 1700. To sell one's soul "make a contract with the devil," often figurative, is from c. 1570. Sell-by in reference to dates stamped on perishable packaged foods is from 1972. To sell like hot cakes is from 1839. To sell (someone) down the river figuratively is by 1927, probably from or with recollection of slavery days, on notion of sale from the Upper South to the cotton plantations of the Deep South (attested in this literal sense since 1851).