The Collaborative International Dictionary of English v.0.48:

Anger \An"ger\ (a[ng]"g[~e]r), n. [OE. anger, angre, affliction,
   anger, fr. Icel. angr affliction, sorrow; akin to Dan. anger
   regret, Swed. [*a]nger regret, AS. ange oppressed, sad, L.
   angor a strangling, anguish, angere to strangle, Gr.
   'a`gchein to strangle, Skr. a[mdot]has pain, and to E.
   anguish, anxious, quinsy, and perh. awe, ugly. The word seems
   to have orig. meant to choke, squeeze. [root]3.]
   1. Trouble; vexation; also, physical pain or smart of a sore,
      etc. [Obs.]
      [1913 Webster]

            I made the experiment, setting the moxa where . . .
            the greatest anger and soreness still continued.
                                                  --Temple.
      [1913 Webster]

   2. A strong passion or emotion of displeasure or antagonism,
      excited by a real or supposed injury or insult to one's
      self or others, or by the intent to do such injury.
      [1913 Webster]

            Anger is like
            A full hot horse, who being allowed his way,
            Self-mettle tires him.                --Shak.
      [1913 Webster]

   Syn: Resentment; wrath; rage; fury; passion; ire gall;
        choler; indignation; displeasure; vexation; grudge;
        spleen.

   Usage: Anger, Indignation, Resentment, Wrath, Ire,
          Rage, Fury. Anger is a feeling of keen displeasure
          (usually with a desire to punish) for what we regard
          as wrong toward ourselves or others. It may be
          excessive or misplaced, but is not necessarily
          criminal. Indignation is a generous outburst of anger
          in view of things which are indigna, or unworthy to be
          done, involving what is mean, cruel, flagitious, etc.,
          in character or conduct. Resentment is often a moody
          feeling, leading one to brood over his supposed
          personal wrongs with a deep and lasting anger. See
          Resentment. Wrath and ire (the last poetical)
          express the feelings of one who is bitterly provoked.
          Rage is a vehement ebullition of anger; and fury is an
          excess of rage, amounting almost to madness. Warmth of
          constitution often gives rise to anger; a high sense
          of honor creates indignation at crime; a man of quick
          sensibilities is apt to cherish resentment; the wrath
          and ire of men are often connected with a haughty and
          vindictive spirit; rage and fury are distempers of the
          soul to be regarded only with abhorrence.
          [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Anger \An"ger\, v. t. [imp. & p. p. Angered; p. pr. & vb. n.
   Angering.] [Cf. Icel. angra.]
   1. To make painful; to cause to smart; to inflame. [Obs.]
      [1913 Webster]

            He . . . angereth malign ulcers.      --Bacon.
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   2. To excite to anger; to enrage; to provoke.
      [1913 Webster]

            Taxes and impositions . . . which rather angered
            than grieved the people.              --Clarendon.
      [1913 Webster]

WordNet (r) 3.0 (2006):

anger
    n 1: a strong emotion; a feeling that is oriented toward some
         real or supposed grievance [syn: anger, choler, ire]
    2: the state of being angry [syn: anger, angriness]
    3: belligerence aroused by a real or supposed wrong (personified
       as one of the deadly sins) [syn: wrath, anger, ire,
       ira]
    v 1: make angry; "The news angered him"
    2: become angry; "He angers easily" [syn: anger, see red]