irascible

from WordNet (r) 3.0 (2006)

irascible
    adj 1: quickly aroused to anger; "a hotheaded commander" [syn:
           {choleric}, {irascible}, {hotheaded}, {hot-tempered},
           {quick-tempered}, {short-tempered}]
    2: characterized by anger; "a choleric outburst"; "an irascible
       response" [syn: {choleric}, {irascible}]

from The Collaborative International Dictionary of English v.0.48

Irascible \I*ras"ci*ble\, a. [L. irascibilis, fr. irasci to be
   angry, ira anger: cf. F. irascible. See {Ire}.]
   Prone to anger; easily provoked or inflamed to anger;
   choleric; irritable; as, an irascible man; an irascible
   temper or mood. -- {I*ras"ci*ble*ness}, n. -- {I*ras"ci*bly},
   adv.
   [1913 Webster]

from Moby Thesaurus II by Grady Ward, 1.0

56 Moby Thesaurus words for "irascible":
      agitable, bearish, bitchy, cankered, cantankerous, churlish,
      contrary, crabbed, cranky, cross, cross-grained, crusty, cussed,
      difficult, disagreeable, edgy, emotional, emotionally unstable,
      eruptive, excitable, explosive, feisty, fractious, froward,
      high-mettled, high-spirited, high-strung, highly emotional,
      huffish, huffy, inflammable, irritable, mean, mettlesome, nervous,
      ornery, perturbable, perverse, prickly, sensitive, skittish,
      snappish, spiteful, spleeny, splenetic, startlish, stuffy, sulky,
      sullen, testy, touchy, ugly, volcanic, waspish, wayward,
      wrongheaded

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