The Collaborative International Dictionary of English v.0.48:

Impassioned \Im*pas"sioned\, p. p. & a.
   Actuated or characterized by passion or zeal; showing warmth
   of feeling; ardent; animated; excited; as, an impassioned
   orator or discourse.
   [1913 Webster]

WordNet (r) 3.0 (2006):

impassioned
    adj 1: characterized by intense emotion; "ardent love"; "an
           ardent lover"; "a fervent desire to change society"; "a
           fervent admirer"; "fiery oratory"; "an impassioned
           appeal"; "a torrid love affair" [syn: ardent,
           fervent, fervid, fiery, impassioned, perfervid,
           torrid]

Moby Thesaurus II by Grady Ward, 1.0:

125 Moby Thesaurus words for "impassioned":
   abandoned, ablaze, afire, agog, amative, amatory, amorous,
   animated, aquiver, ardent, aroused, atingle, atwitter, blazing,
   boiling over, breathless, burning, bursting, carried away,
   committed, cordial, dedicated, deep, delirious, desirous, devoted,
   devout, dithyrambic, drunk, eager, earnest, ebullient,
   effervescent, emotional, emphatic, enthusiastic, erotic, excited,
   exciting, exhilarated, exuberant, faithful, febrile, fervent,
   fervid, fevered, feverish, fierce, fiery, fired, flaming, flushed,
   furious, glowing, gushing, gushy, hearty, heated, high, hopped up,
   hot, hot-blooded, in earnest, inflamed, inspired, intense, intent,
   intent on, intoxicated, keen, keyed up, lascivious, lathered up,
   lively, loverlike, loverly, loyal, manic, maudlin, melodramatic,
   moved, mushy, on fire, overemotional, overheated, passionate,
   perfervid, profound, provoking, ready to burst, red-hot, resolute,
   romantic, roused, rousing, sentimental, serious, sexual, sincere,
   spirited, steamed up, steaming, steamy, stimulated, stimulating,
   stirred, stirred up, stirring, thrilled, tingling, tingly, torrid,
   turned-on, unrestrained, urgent, vehement, vigorous, violent, warm,
   whipped up, white-hot, worked up, wrought up, yeasty, zealous