The Collaborative International Dictionary of English v.0.48:

Unapproving \Unapproving\
   See approving.

Moby Thesaurus II by Grady Ward, 1.0:

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