c.1386, "lacking strength," from un- (1) "not" + O.E. wielde "active, vigorous," from P.Gmc. *walth- "have power" (see wield). Meaning "moving ungracefully" is recorded from 1530; in ref. to weapons, "difficult to handle, awkward by virtue of size or shape" it is attested from 1547.
[uhn-weel-dee] 
di