earthyoudaoicibaDictYouDict[earth 词源字典]
earth: [OE] Earth comes ultimately from an Indo- European base *er-. This produced the prehistoric Germanic noun *erthō, ancestor of German erde, Dutch aarde (whence, via early Afrikaans, English aardvark [19], literally ‘earth-pig’), Swedish and Danish jord, and English earth. Related forms outside Germanic include Greek eraze ‘on the ground’ and Welsh erw ‘field’. The word’s basic range of modern senses, ‘ground’, ‘world’, and ‘soil’, all date back to the Old English period.
=> aardvark[earth etymology, earth origin, 英语词源]
bot (n.)youdaoicibaDictYouDict
in Internet sense, c. 2000, short for robot. Its modern use has curious affinities with earlier uses, such as "parasitical worm or maggot" (1520s), of unknown origin; and Australian-New Zealand slang "worthless, troublesome person" (World War I-era). The method of minting new slang by clipping the heads off words does not seem to be old or widespread in English. Examples (za from pizza, zels from pretzels, rents from parents) are American English student or teen slang and seem to date back no further than late 1960s.
CastileyoudaoicibaDictYouDict
medieval Spanish county and later kingdom, from Vulgar Latin castilla, from Latin castella, plural of castellum "castle, fort, citadel, stronghold" (see castle (n.)); so called in reference to the many fortified places there during the Moorish wars. The name in Spanish is said to date back to c.800. Related: Castilian. As a fine kind of soap, in English from 1610s.
football (n.)youdaoicibaDictYouDict
open-air game involving kicking a ball, c. 1400; in reference to the inflated ball used in the game, mid-14c. ("Þe heued fro þe body went, Als it were a foteballe," Octavian I manuscript, c. 1350), from foot (n.) + ball (n.1). Forbidden in a Scottish statute of 1424. One of Shakespeare's insults is "you base foot-ball player" [Lear I.iv]. Ball-kicking games date back to the Roman legions, at least, but the sport seems first to have risen to a national obsession in England, c. 1630. Figurative sense of "something idly kicked around, something subject to hard use and many vicissitudes" is by 1530s.

Rules of the game first regularized at Cambridge, 1848; soccer (q.v.) split off in 1863. The U.S. style (known to some in England as "stop-start rugby with padding") evolved gradually 19c.; the first true collegiate game is considered to have been played Nov. 6, 1869, between Princeton and Rutgers, at Rutgers, but the rules there were more like soccer. A rematch at Princeton Nov. 13, with the home team's rules, was true U.S. football. Both were described as foot-ball at Princeton.
Then twenty-five of the best players in college were sent up to Brunswick to combat with the Rutgers boys. Their peculiar way of playing this game proved to Princeton an insurmountable difficulty; .... Two weeks later Rutgers sent down the same twenty-five, and on the Princeton grounds, November 13th, Nassau played her game; the result was joyous, and entirely obliterated the stigma of the previous defeat. ["Typical Forms of '71" by the Princeton University Class of '72, 1869]
lieutenant (n.)youdaoicibaDictYouDict
late 14c., "one who takes the place of another," from Old French lieu tenant "substitute, deputy," literally "placeholder," from lieu "place" (see lieu) + tenant, present participle of tenir "to hold" (see tenant). The notion is of a "substitute" for higher authority. Specific military sense of "officer next in rank to a captain" is from 1570s. Pronunciation with lef- is common in Britain, and spellings to reflect it date back to 14c., but the origin of this is a mystery (OED rejects suggestion that it comes from old confusion of -u- and -v-).
thimble (n.)youdaoicibaDictYouDict
Old English þymel "sheath or covering for the thumb," from thuma (see thumb (n.)) + -el (1), used in forming names of instruments (compare handle). Excrescent -b- began mid-15c. (compare humble, nimble). Originally of leather, metal ones came into use 17c. Related: Thimbleful. Thimblerig, con game played with three thimbles and a pea or button, is attested from 1825 by this name, though references to thimble cheats, probably the same swindle, date back to 1716 (see rig (v.)).