The Collaborative International Dictionary of English v.0.48:

pang \pang\ (p[a^]ng), n. [Prob. for older prange. Cf. Prong.]
   A paroxysm of extreme pain or anguish; a sudden and
   transitory agony; a throe; as, the pangs of death.
   [1913 Webster]

   Syn: Agony; anguish; distress. See Agony.
        [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Pang \Pang\, v. t.
   To torture; to cause to have great pain or suffering; to
   torment. [R.] --Shak.
   [1913 Webster]

WordNet (r) 3.0 (2006):

pang
    n 1: a sudden sharp feeling; "pangs of regret"; "she felt a stab
         of excitement"; "twinges of conscience" [syn: pang,
         stab, twinge]
    2: a mental pain or distress; "a pang of conscience" [syn:
       pang, sting]
    3: a sharp spasm of pain

Moby Thesaurus II by Grady Ward, 1.0:

73 Moby Thesaurus words for "pang":
   ache, aching, acute pain, anguish, bite, blow, boring pain,
   charley horse, contriteness, contrition, cramp, cramps, crick, cut,
   darting pain, discomfort, distress, dolor, fulgurant pain,
   girdle pain, gnawing, grief, griping, guilt, hesitation, hitch,
   hurt, injury, jumping pain, kink, lancinating pain, lesion,
   malaise, misery, misgiving, mortification, nasty blow, nip, pain,
   paroxysm, passion, pinch, prick, qualm, regret, remorse, scruple,
   seizure, self-reproach, sharp pain, shock, shoot, shooting,
   shooting pain, sore, sore spot, spasm, stab, stabbing pain, stitch,
   stress, stress of life, stroke, suffering, tender spot, thrill,
   throes, tormen, tweak, twinge, twitch, wound, wrench