The Collaborative International Dictionary of English v.0.48:

Invidious \In*vid"i*ous\, a. [L. invidiosus, fr. invidia envy.
   See Envy, and cf. Envious.]
   [1913 Webster]
   1. Envious; malignant. [Obs.] --Evelyn.
      [1913 Webster]

   2. Worthy of envy; desirable; enviable. [Obs.]
      [1913 Webster]

            Such a person appeareth in a far more honorable and
            invidious state than any prosperous man. --Barrow.
      [1913 Webster]

   3. Likely to or intended to incur or produce ill will, or to
      provoke envy or resentment; hateful; offensive; as,
      invidious distinctions.
      [1913 Webster]

            Agamemnon found it an invidious affair to give the
            preference to any one of the Grecian heroes.
                                                  --Broome.
      -- In*vid"i*ous*ly, adv. -- In*vid"i*ous*ness, n.
      Invigilance

WordNet (r) 3.0 (2006):

invidious
    adj 1: containing or implying a slight or showing prejudice;
           "discriminatory attitudes and practices"; "invidious
           comparisons" [syn: discriminatory, invidious]

Moby Thesaurus II by Grady Ward, 1.0:

50 Moby Thesaurus words for "invidious":
   abhorrent, abominable, baleful, begrudging, bitchy, bitter,
   calumnious, covetous, cussed, defamatory, desirous of, detestable,
   detracting, detractory, distrustful, envious, envying, green,
   green with envy, green with jealousy, green-eyed, grudging,
   harmful, hateful, horn-mad, iniquitous, jaundice-eyed, jaundiced,
   jealous, malefic, maleficent, malicious, malign, malignant,
   maligning, mean, nasty, noxious, obnoxious, odious, ornery,
   repellent, revulsive, scandalous, slanderous, suspicious,
   vilifying, wicked, yellow, yellow-eyed