The Collaborative International Dictionary of English v.0.48:

Uncomplimentary \Uncomplimentary\
   See complimentary.

WordNet (r) 3.0 (2006):

uncomplimentary
    adj 1: showing or representing unfavorably; "an unflattering
           portrait"; "an uncomplimentary dress" [syn:
           unflattering, uncomplimentary] [ant: flattering]
    2: tending to (or intended to) detract or disparage [ant:
       complimentary]

Moby Thesaurus II by Grady Ward, 1.0:

29 Moby Thesaurus words for "uncomplimentary":
   against, con, depreciative, depreciatory, detracting,
   disadvantageous, disappointed, disapprobatory, disapproving,
   discontented, disenchanted, disgruntled, disillusioned,
   disparaging, displeased, dissatisfied, dissenting, indignant, low,
   opposed, opposing, pejorative, poor, slighting, turned-off,
   unappreciative, unapproving, unfavorable, unhappy