soothe

Origin

From Middle English sothen (“to verify, prove the validity of”), from Old English sōþian (“to verify, prove, confirm, bear witness to”), from Proto-West Germanic *sanþōn, from Proto-Germanic *sanþōną (“to prove, certify, acknowledge, testify”), from Proto-Indo-European *h₁es- (“to be”). Cognate with Danish sande (“to verify”), Swedish sanna (“to verify”), Icelandic sanna (“to verify”). See also sooth. Displaced Old English frēfran, ġefrēfran (“to comfort, console, soothe”), and partially displaced Old English stillan, ġestillan (“to calm, become calm, pacify, quieten”) (whence modern still). The semantic evolution of "to verify, prove the validity of" → "to comfort" (first attested in the late 17th century) comes from the notion of assuaging someone by supporting the truth of what they say.