lambaste v.

"beat with a stick, thrash," 1530s, perhaps from the cookery sense of baste (v.2) or from Old Norse beysta "to beat" or a similar Scandinavian source (such as Swedish basa "to beat, flog," bösta "to thump"), from Proto-Germanic *baut-sti-, from PIE root *bhau- "to strike."

"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.

"hit hard," by 1846, probably an alteration of baste "beat" (see lambaste) influenced by some sense of paste (n.1). Related: Pasted; pasting.