The Collaborative International Dictionary of English v.0.48:

Commiserate \Com*mis"er*ate\, v. t. [imp. & p. p.
   Commiserated; p. pr. & vb. n. Commiserating.] [L.
   commiseratus, p. p. of commiserari to commiserate; com- +
   miserari to pity. See Miserable.]
   To feel sorrow, pain, or regret for; to pity.
   [1913 Webster]

         Then must we those, who groan, beneath the weight
         Of age, disease, or want, commiserate.   --Denham.
   [1913 Webster]

         We should commiserate our mutual ignorance. --Locke.

   Syn: To pity; compassionate; lament; condole.
        [1913 Webster]

WordNet (r) 3.0 (2006):

commiserate
    v 1: to feel or express sympathy or compassion [syn:
         commiserate, sympathize, sympathise]

Moby Thesaurus II by Grady Ward, 1.0:

23 Moby Thesaurus words for "commiserate":
   ache, be sorry for, bleed, bleed for, comfort, compassionate,
   condole with, console, express sympathy for, feel for,
   feel sorrow for, feel sorry for, feel with, grieve for,
   grieve with, lament for, pity, sorrow with, speak soothing words,
   sympathize, sympathize with, weep for, weep with