1560s, originally "weak beer;" used figuratively of small things or trifling matters. Small with the meaning "of low alcoholic content" is attested from mid-15c.
also short-circuit, 1854, in electricity, "a shunt connecting two parts of an electric current so as to carry a greater part of it," from short (adj.) + circuit (n.). As a verb, "introduce a shunt of low resistance into an electric current," from 1867; intransitive sense from 1902; in the figurative sense by 1899. Related: Short-circuited; short-circuiting.
place where vagabonds, low-lifes, and out-of-work men gather in a town, 1921, with reference to Seattle, Washington, U.S., a variant of skid road "track of skids along which logs are rolled" (1851); see skid (n.); the sense of which was extended to "part of town inhabited by loggers" (1906), then, by hobos, to "disreputable district" (1915); probably shaded by the notion of "go downhill."
to eat humble pie (1830) is from umble pie (1640s), pie made from umbles "edible inner parts of an animal" (especially deer), considered a low-class food. The similar sense of similar-sounding words (the "h" of humble (adj.) was not then pronounced) converged to make the pun. Umbles is Middle English numbles "offal," with loss of n- through assimilation into preceding article.
slang for "drunk," 1736, sometimes said to be from notion of a ship heavy-laden and so low in the water that small waves (half seas) wash over the deck. This suits the sense, but the phrase is not recorded in this alleged literal sense. Half seas over "halfway across the sea" is recorded from 1550s, however, and it was given a figurative extension to "halfway through a matter" by 1690s. What drunkenness is halfway to is not clear.
1837, from Greek hoi polloi (plural) "the people," literally "the many" (plural of polys, from PIE root *pele- (1) "to fill"). Used in Greek by Dryden (1668) and Byron (1822), in both cases preceded by the, even though Greek hoi means "the," a mistake repeated often by subsequent writers who at least have the excuse of ignorance of Greek. Ho "the" is from PIE *so- "this, that" (nominative), cognate with English the and Latin sic. From the adjective agoraios "pertaining to the agora; frequenting the market" Greek had hoi agoraioi "loungers in the market, loafers, common, low men."