M.E. compound of ful "full" + -som "some." Sense evolved from "abundant, full" (c.1250) to "plump, well-fed" (c.1350) to "overgrown, overfed" (1642) and thus, of language, "offensive to taste or good manners" (1663). Since the 1960s, however, it commonly has been used in its original, favorable sense, especially in fulsome praise.