Etymology: Related to clumse v., although the actual nature of the relation is not clear. Kindred words appear in modern Scandinavian: compare Icelandic klumsa, klumsi, lock-jawed, speechless, Swedish dialect klumsen, adjective, benumbed with cold, clemmed with hunger, dazed, klumsi(g), in southern Sweden, benumbed with cold, clumsy, klumshändt, numbed in the hands; also klums, noun, a numbskull. The localization of the word in England agrees with a Norse origin.

Etymology: Middle English clumsen found in 13th cent., perhaps represents an Old English *clumsian , on the type of rótsian to be cheerful, hlǽnsian to make lean, etc. But it may be of Norse origin: compare modern Norwegian klumsa , intensive of kluma , to make motionless, speechless, lame, etc. Simpler forms of the same root appear in East Frisian klömen to be numb with cold, West Frisian klomjen , Low German klömen , klomen , klaomen , Dutch kleumen , Swedish klömen ; also, in compounds, Middle German verklummen , Middle Dutch verkleumen , verkloemen . The stem klum- is in ablaut relation to klam- in clam n.¹ and clem v.¹, the radical notion being that of ‘confinement, constraint, constriction’, which, in this group, is especially referred to the stiffening action of cold.