dead end (n.)youdaoicibaDictYouDict[dead end 词源字典]
"closed end of a passage," 1886, from dead (adj.) + end (n.). Figurative use is attested from 1922. As an adjective, from 1928; as a verb, from 1921. Related: Deadender (by 1996).[dead end etymology, dead end origin, 英语词源]
dead man's hand (n.)youdaoicibaDictYouDict
in poker, pair of aces and pair of eights, supposedly what Wild Bill Hickock held when Jack McCall shot him in 1876.
dead reckoning (n.)youdaoicibaDictYouDict
"ascertaining the position of a ship by measurement of the distance run," 1610s, might be from nautical abbreviation ded. ("deduced") in log books, but it also fits dead (adj.) in the sense of "unrelieved, absolute."
Dead SeayoudaoicibaDictYouDict
mid-13c., from dead (adj.) + sea; its water is 26 percent salt (as opposed to 3 or 4 percent in most oceans) and supports practically no life. In the Bible it was the "Salt Sea" (Hebrew yam hammelah), also "Sea of the Plain" and "East Sea." In Arabic it is al-bahr al-mayyit "Dead Sea." The ancient Greeks knew it as he Thalassa asphaltites "the Asphaltite Sea." Latin Mare Mortum, Greek he nekra thalassa (both "The Dead Sea") referred to the sea at the northern boundaries of Europe, the Arctic Ocean.
deadbeat (n.)youdaoicibaDictYouDict
"worthless sponging idler," 1863, American English slang, perhaps originally Civil War slang, from dead (adj.) + beat. Earlier used colloquially as an adjectival expression to mean "completely beaten" (1821), and perhaps the base notion is of "worn out, good for nothing." It is noted in a British source from 1861 as a term for "a pensioner."
In England "dead beat" means worn out, used up. ... But here, "dead beat" is used, as a substantive, to mean a scoundrel, a shiftless, swindling vagabond. We hear it said that such a man is a beat or a dead beat. The phrase thus used is not even good slang. It is neither humorous nor descriptive. There is not in it even a perversion of the sense of the words of which it is composed. Its origin is quite beyond conjecture. ["Americanisms," in "The Galaxy," January 1878]
It also was used of a kind of regulating mechanism in pendulum clocks.
deaden (v.)youdaoicibaDictYouDict
1660s "deprive of or diminish (some quality)," from dead (adj.) + -en (1). Earlier the verb was simply dead. Related: Deadened; deadening.
Deadhead (n.)youdaoicibaDictYouDict
by 1974 in sense of "devotee of the rock music band the Grateful Dead;" earlier (with lower-case) "one who rides for free on the railroads" (1866), and "non-paying spectator" (1841).
deadline (n.)youdaoicibaDictYouDict
"time limit," 1920, American English newspaper jargon, from dead (adj.) + line (n.). Perhaps influenced by earlier use (1864) to mean the "do-not-cross" line in Civil War prisons, which figured in the Wirz trial.
And he, the said Wirz, still wickedly pursuing his evil purpose, did establish and cause to be designated within the prison enclosure containing said prisoners a "dead line," being a line around the inner face of the stockade or wall enclosing said prison and about twenty feet distant from and within said stockade; and so established said dead line, which was in many places an imaginary line, in many other places marked by insecure and shifting strips of [boards nailed] upon the tops of small and insecure stakes or posts, he, the said Wirz, instructed the prison guard stationed around the top of said stockade to fire upon and kill any of the prisoners aforesaid who might touch, fall upon, pass over or under across the said "dead line" .... ["Trial of Henry Wirz," Report of the Secretary of War, Oct. 31, 1865]
deadlock (n.)youdaoicibaDictYouDict
"complete standstill," from dead (adj.), in its emphatic use, + lock (n.). First attested 1779 in Sheridan's play "The Critic."
deadly (adj.)youdaoicibaDictYouDict
Old English deadlic "mortal, subject to death," also "causing death;" see dead + -ly (1). Meaning "having the capacity to kill" is from late 14c. (Old English words for this included deaðbærlic, deaðberende).
deadpanyoudaoicibaDictYouDict
1928, from dead (adj.) + pan (n.) in slang sense of "face."
deadweight (n.)youdaoicibaDictYouDict
1650s, "weight of an inert body," from dead (adj.) + weight (n.).
deadwood (n.)youdaoicibaDictYouDict
1887 in figurative sense of "useless person or thing," originally American English, from dead (adj.) + wood (n.). Dead wood in a forest is useful as firewood; perhaps the reference here is to the dried up parts of plants grown for commercial production of flowers or fruit.
deaf (adj.)youdaoicibaDictYouDict
Old English deaf "deaf," also "empty, barren," specialized from Proto-Germanic *daubaz (cognates: Old Saxon dof, Old Norse daufr, Old Frisian daf, Dutch doof "deaf," German taub, Gothic daufs "deaf, insensate"), from PIE dheubh-, which was used to form words meaning "confusion, stupefaction, dizziness" (cognates: Greek typhlos "blind," typhein "to make smoke;" Old English dumb "unable to speak;" Old High German tumb).

The word was pronounced to rhyme with reef until 18c. Deaf-mute is from 1837, after French sourd-muet. Deaf-mutes were sought after in 18c.-19c. Britain as fortune-tellers. Deaf as an adder (Old English) is from Psalms lviii:5.
deafen (v.)youdaoicibaDictYouDict
1590s, "to make deaf," from deaf + -en (1). The earlier verb was simply deaf (mid-15c.). For "to become deaf, to grow deaf," Old English had adeafian (intransitive), which survived into Middle English as deave but then took on a transitive sense from mid-14c. and sank from use except in dialects (where it mostly has transitive and figurative senses), leaving English without an intransitive verb here.
deafening (adj.)youdaoicibaDictYouDict
"very loud," 1590s, from present participle of deafen (q.v.). Deafening silence is attested by 1830.
deafness (n.)youdaoicibaDictYouDict
late 14c., from deaf + -ness.
deal (n.1)youdaoicibaDictYouDict
from Old English dæl "part, share, quantity, amount," from Proto-Germanic *dailaz (cognates: Old Norse deild, Old Frisian del, Dutch deel, Old High German and German teil, Gothic dails "part, share"), from PIE *dail- "to divide" (cognates: Old Church Slavonic delu "part," Lithuanian dalis).

Business sense of "transaction, bargain" is 1837, originally slang. Meaning "an amount" is from 1560s. New Deal is from F.D. Roosevelt speech of July 1932. Big deal is 1928; ironic use first recorded 1951 in "Catcher in the Rye." Deal breaker is attested by 1975.
deal (n.2)youdaoicibaDictYouDict
"plank or board of pine," c. 1400, from Low German (compare Middle Low German dele), from Proto-Germanic *theljon, from PIE root *tel- "ground, floor." An Old English derivative was þelu "hewn wood, board, flooring."
deal (v.)youdaoicibaDictYouDict
Old English dælan "to divide, distribute, separate, share, bestow, dispense," from the source of deal (n.). Meaning "to distribute cards before a game" is from 1520s. To deal with "handle" is attested from mid-15c. Related: Dealt; dealing.