The Collaborative International Dictionary of English v.0.48:

Insult \In"sult\, n. [L. insultus, fr. insilire to leap upon:
   cf. F. insulte. See Insult, v. t.]
   [1913 Webster]
   1. The act of leaping on; onset; attack. [Obs.] --Dryden.
      [1913 Webster]

   2. Gross abuse offered to another, either by word or act; an
      act or speech of insolence or contempt; a deprecatory
      remark; an affront; an indignity.
      [1913 Webster]

            The ruthless sneer that insult adds to grief.
                                                  --Savage.

   3. (Med., Biology) An injury to an organism; trauma; as, to
      produce an experimental insult to investigate healing
      processes.
      [PJC]

   Syn: Affront; indignity; abuse; outrage; contumely. See
        Affront.
        [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Insult \In*sult"\, v. t. [imp. & p. p. Insulted; p. pr. & vb.
   n. Insulting.] [F. insulter, L. insultare, freq. fr.
   insilire to leap into or upon; pref. in- in, on + salire to
   leap. See Salient.]
   [1913 Webster]
   1. To leap or trample upon; to make a sudden onset upon.
      [Obs.] --Shak.
      [1913 Webster]

   2. To treat with abuse, insolence, indignity, or contempt, by
      word or action; to abuse; as, to call a man a coward or a
      liar, or to sneer at him, is to insult him.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Insult \In*sult"\, v. i.
   1. To leap or jump.
      [1913 Webster]

            Give me thy knife, I will insult on him. --Shak.
      [1913 Webster]

            Like the frogs in the apologue, insulting upon their
            wooden king.                          --Jer. Taylor.
      [1913 Webster]

   2. To behave with insolence; to exult. [Archaic]
      [1913 Webster]

            The lion being dead, even hares insult. --Daniel.
      [1913 Webster]

            An unwillingness to insult over their helpless
            fatuity.                              --Landor.
      [1913 Webster]

WordNet (r) 3.0 (2006):

insult
    n 1: a rude expression intended to offend or hurt; "when a
         student made a stupid mistake he spared them no abuse";
         "they yelled insults at the visiting team" [syn: abuse,
         insult, revilement, contumely, vilification]
    2: a deliberately offensive act or something producing the
       effect of deliberate disrespect; "turning his back on me was
       a deliberate insult" [syn: insult, affront]
    v 1: treat, mention, or speak to rudely; "He insulted her with
         his rude remarks"; "the student who had betrayed his
         classmate was dissed by everyone" [syn: diss, insult,
         affront]