WordNet (r) 3.0 (2006):

undignified
    adj 1: lacking dignity [ant: dignified]

Moby Thesaurus II by Grady Ward, 1.0:

45 Moby Thesaurus words for "undignified":
   Doric, barbaric, barbarous, cacophonous, chintzy, clumsy, coarse,
   crude, doggerel, dysphemistic, graceless, gross, harsh, improper,
   impure, in bad taste, inappropriate, inconcinnate, inconcinnous,
   incorrect, indecent, indecorous, indelicate, inelegant,
   infelicitous, low, offensive, outlandish, rude, tasteless,
   unbecoming, unbeseeming, uncourtly, uncouth, uneuphonious,
   unfelicitous, unfitting, ungenteel, ungraceful, unpolished,
   unrefined, unseemly, unsuitable, untasteful, vulgar