The Collaborative International Dictionary of English v.0.48:

Ire \Ire\, n. [F., fr. L. ira.]
   Anger; wrath. [Poet.]

   Syn: Anger; passion; rage; fury. See Anger.
        [1913 Webster]

WordNet (r) 3.0 (2006):

ire
    n 1: a strong emotion; a feeling that is oriented toward some
         real or supposed grievance [syn: anger, choler, ire]
    2: belligerence aroused by a real or supposed wrong (personified
       as one of the deadly sins) [syn: wrath, anger, ire,
       ira]

Moby Thesaurus II by Grady Ward, 1.0:

23 Moby Thesaurus words for "ire":
   a transient madness, anger, angriness, enrage, enragement, fury,
   grapes of wrath, heat, incense, indignation, infuriate,
   infuriation, irateness, mad, madden, rage, saeva indignatio,
   soreness, steam up, umbrage, vials of wrath, wrath, wrathfulness