pieceyoudaoicibaDictYouDict[piece 词源字典]
piece: [13] Piece is probably ultimately of Celtic origin. It comes via Anglo-Norman pece from medieval Latin pecia or petia, which appears to have been borrowed from *pettia, an unrecorded word in the Celtic language of ancient Gaul. This would have been descended from an Old Celtic base *pett- that may also be the source of English peat [14]. Anglo-Norman *peche, a variant form of pece, of dialectal origin, gave English patch [14].
=> patch, peat[piece etymology, piece origin, 英语词源]
piece (n.)youdaoicibaDictYouDict
c. 1200, "fixed amount, measure, portion," from Old French piece "piece, bit portion; item; coin" (12c.), from Vulgar Latin *pettia, probably from Gaulish *pettsi (compare Welsh peth "thing," Breton pez "piece, a little"), perhaps from an Old Celtic base *kwezd-i-, from PIE root *kwezd- "a part, piece" (cognates: Russian chast' "part"). Related: Pieces.

Sense of "portable firearm" first recorded 1580s; that of "chessman" is from 1560s. Meaning "person regarded as a sex object" is first recorded 1785 (compare piece of ass, human beings colloquially called piece of flesh from 1590s; also compare Latin scortum "bimbo, anyone available for a price," literally "skin"). Meaning "a portion of a distance" is from 1610s; that of "literary composition" dates from 1530s. Piece of (one's) mind is from 1570s. Piece of work "remarkable person" echoes Hamlet. Piece as "a coin" is attested in English from 1570s, hence Piece of eight, old name for the Spanish dollar (c. 1600) of the value of 8 reals.
PIECE. A wench. A damned good or bad piece; a girl who is more or less active and skilful in the amorous congress. Hence the (Cambridge) toast, may we never have a PIECE (peace) that will injure the constitution. ["Dictionary of Buckish Slang, University Wit and Pickpocket Eloquence," London, 1811]
piece (v.)youdaoicibaDictYouDict
"to mend by adding pieces," late 14c., from piece (n.). Sense of "to join, unite, put together" is from late 15c. Related: Pieced; piecing.