"feeling of offense, resentment, sullen anger," 1570s, duggin, of unknown origin. One suggestion is Italian aduggiare "to overshadow," giving it the same sense development as umbrage. No clear connection to earlier dudgeon (late 14c.), a kind of wood used for knife handles, which is perhaps from French douve "a stave," which probably is Germanic. The source also has been sought in Celtic, especially Welsh dygen "malice, resentment," but OED reports that this "appears to be historically and phonetically baseless."