left-handed (adj.)youdaoicibaDictYouDict[left-handed 词源字典]
late 14c., of persons; 1650s of tools, etc., from left (adj.) + -handed. In 15c. it also could mean "maimed." Sense of "underhanded" is from early 17c., as in left-handed compliment (1787, also attested 1855 in pugilism slang for "a punch with the left fist"), as is that of "illicit" (as in left-handed marriage). Related: Left-handedly; left-handedness.[left-handed etymology, left-handed origin, 英语词源]
mancinism (n.)youdaoicibaDictYouDict
"left-handedness," 1890, from Italian mancinissmo, from mancino "infirm (in the hand)," from manco, from Latin mancus "maimed, infirm, crippled, lame-handed" (see manque).