Source : Webster's Revised Unabridged Dictionary (1913)

Verb \Verb\, n. [F. verbe, L. verbum a word, verb. See {Word}.]
   1. A word; a vocable. [Obs.] --South.

   2. (Gram.) A word which affirms or predicates something of
      some person or thing; a part of speech expressing being,
      action, or the suffering of action.

   Note: A verb is a word whereby the chief action of the mind
         [the assertion or the denial of a proposition] finds
         expression. --Earle.

   {Active verb}, {Auxiliary verb}, {Neuter verb}, etc. See
      {Active}, {Auxiliary}, {Neuter}, etc.

Source : WordNet®

verb
     n 1: a word that serves as the predicate of a sentence
     2: a content word that denotes an action or a state