c. 1300, "one who slaughters animals for market," from Anglo-French boucher, from Old French bochier "butcher, executioner" (12c., Modern French boucher), probably literally "slaughterer of goats," from bouc "male goat," from Frankish *bukk or some other Germanic source (see buck (n.1)) or Celtic *bukkos "he-goat." Figurative sense of "brutal murderer, one who kills indiscriminately or cruelly" is attested from 1520s. Related: Butcherly. Old English had flæscmangere "butcher" ('flesh-monger').
1560s, "to kill or slaughter for food or market," from butcher (n.). Figuratively, "to bungle, botch, spoil by bad work," 1640s. Related: Butchered; butchering. Re-nouned 1640s as butcherer.