unappreciative

from WordNet (r) 3.0 (2006)

unappreciative
    adj 1: not feeling or expressing gratitude; "unappreciative of
           nature's bounty"

from Moby Thesaurus II by Grady Ward, 1.0

26 Moby Thesaurus words for "unappreciative":
      against, con, disappointed, disapprobatory, disapproving,
      discontented, disenchanted, disgruntled, disillusioned, displeased,
      dissatisfied, dissenting, indignant, low, opposed, opposing, poor,
      thankless, turned-off, unapproving, uncomplimentary, unfavorable,
      ungrateful, unhappy, unmindful, unthankful