Lam
late 16th century: perhaps of Scandinavian origin and related to Norwegian and Danish lamme ‘paralyse’.
wiktionary
From Middle English lamen, lemen, from Old English lemian and Old Norse lemja; both from Proto-Germanic *lamjaną.
From Arabic لَام (lām), the name of the letter ل (l).
etymonline
lam (n.)
"flight, escape," as in on the lam, 1928, in pickpocket slang, (according to OED attested from 1897 in do a lam), from a U.S. slang verb meaning "to run off" (1886), of uncertain origin, but perhaps from lam (v.), which was used in British student slang for "to beat" since 1590s (compare lambaste); if so, the word has the same etymological sense as the slang expression beat it.
lam (v.)
also lamm, "to thrash, beat," 1590s, a slang, provincial or colloquial word, probably from Old Norse lemja "to beat," literally "to lame," which is cognate with the native verb lame (see lame (adj.)). Related: Lammed; lamming.
