Word Origin & History
late 12c., buhsum "humble, obedient," from *buh- stem of O.E. bugen "to bow" + -som, for a total meaning "capable of being bent." Meaning progressed from "compliant, obliging," through "lively, jolly," "healthily plump, vigorous," to (in women, and perhaps influenced by lusty) "plump, comely" (1580s).
Du. buigzaam, Ger. biegsam "flexible, pliable" hew closer to the original sense of the English cognate.