"low in price, that may be bought at small cost," c. 1500, ultimately from Old English noun ceap "traffic, a purchase," from ceapian (v.) "to trade, buy and sell," probably from early Germanic borrowings of Latin caupo "petty tradesman, huckster, peddler," cauponari "to haggle" (see chapman). Compare, from the same borrowing, German kaufen "to buy," Old Norse kaupa "to bargain, barter," Gothic kaupon "to traffic, trade."

The sense evolution is from the noun meaning "a barter, a purchase" to "a purchase as rated by the buyer," hence the adjectival meaning "inexpensive," the main modern sense, via Middle English phrases such as god chep "favorable bargain" (12c., a translation of French a bon marché).

The sense of "lightly esteemed, common" is from 1590s (compare similar evolution of Latin vilis). The meaning "low in price" was represented in Old English by undeor, literally "un-dear" (but deop ceap, literally "deep cheap," meant "high price").

The word also was used in Old English for "market" (as in ceapdæg "market day"), a sense surviving in place names Cheapside, East Cheap, etc. To do something on the cheap "with very little expense" is from 1859. Cheap shot originally was U.S. football jargon for a head-on tackle; extended sense "unfair hit" in politics, etc. is by 1968.

German billig "cheap" is from Middle Low German billik, originally "fair, just," with a sense evolution via billiger preis "fair price," etc.

"policeman," 1846; probably an agent noun from the verb cop "to seize, to catch, capture or arrest as a prisoner" (see cop (v.)).

"small vessel used to contain liquids generally; drinking vessel," Old English cuppe, Old Northumbrian copp, from Late Latin cuppa "cup" (source of Italian coppa, Spanish copa, Old French coupe "cup"), from Latin cupa "tub, cask, tun, barrel," which is thought to be cognate with Sanskrit kupah "hollow, pit, cave," Greek kype "gap, hole; a kind of ship," Old Church Slavonic kupu, Lithuanian kaupas "heap," Old Norse hufr "ship's hull," Old English hyf "beehive." De Vaan writes that all probably are from "a non-IE loanword *kup- which was borrowed by and from many languages."

The Late Latin word was borrowed throughout Germanic: Old Frisian kopp "cup, head," Middle Low German kopp "cup," Middle Dutch coppe, Dutch kopje "cup, head." German cognate Kopf now means exclusively "head" (compare French tête, from Latin testa "potsherd").

Used of any thing with the shape of a cup by c. 1400; sense of "quantity contained in a cup" is from late 14c. Meaning "part of a bra that holds a breast" is from 1938. Sense of "cup-shaped metal vessel offered as a prize in sport or games" is from 1640s. Sense of "suffering to be endured" (late 14c.) is a biblical image (Matthew xx.22, xxvi.39) on the notion of "something to be partaken of."

To be in one's cups "intoxicated" is from 1610s (Middle English had cup-shoten "drunk, drunken," mid-14c.). [One's] cup of tea "what interests one" is by 1932, earlier used of persons (1908), the sense being "what is invigorating." Cup-bearer "attendant at a feast who conveys wine or other liquor to guests" is from early 15c.

by 1942, noun ("a cowardly escape, an evasion") and verb ("sneak off, escape, give up without trying"), American English slang, perhaps from cop a plea (c. 1925) "plead guilty to lesser charges," which is probably from northern British slang cop "to catch" (a scolding, etc.); as in cop a feel "grope someone" (1930s); see cop (v.). Sense of "evade an issue or problem" is from 1960s.

Proto-Indo-European root meaning "to grasp."

It might form all or part of: accept; anticipate; anticipation; behave; behoof; behoove; cable; cacciatore; caitiff; capable; capacious; capacity; capias; capiche; capstan; caption; captious; captivate; captive; captor; capture; case (n.2) "receptacle;" catch; catchpoll; cater; chase (n.1) "a hunt;" chase (v.) "to run after, hunt;" chasse; chasseur; conceive; cop (v.) "to seize, catch;" copper (n.2) "policeman;" deceive; emancipate; except; forceps; gaffe; haft; have; hawk (n.); heave; heavy; heft; incapacity; inception; incipient; intercept; intussusception; manciple; municipal; occupy; participation; perceive; precept; prince; purchase; receive; recipe; recover; recuperate; sashay; susceptible.

It might also be the source of: Sanskrit kapati "two handfuls;" Greek kaptein "to swallow, gulp down," kope "oar, handle;" Latin capax "able to hold much, broad," capistrum "halter," capere "to grasp, lay hold; be large enough for; comprehend;" Lettish kampiu "seize;" Old Irish cacht "servant-girl," literally "captive;" Welsh caeth "captive, slave;" Gothic haban "have, hold;" Old English hæft "handle," habban "to have, hold."