Source : Webster's Revised Unabridged Dictionary (1913)

Rodent \Ro"dent\, a. [L. rodens, -entis, p. pr. of rodere to
   gnaw. See {Rase}, v. t., and cf. {Rostrum}.]
   1. Gnawing; biting; corroding; (Med.) applied to a
      destructive variety of cancer or ulcer.

   2. (Zo["o]l.)
      (a) Gnawing.
      (b) Of or pertaining to the Rodentia.

Rodent \Ro"dent\, n. (Zo["o]l.)
   One of the Rodentia.

Source : WordNet®

rodent
     n : relatively small gnawing animals having a single pair of
         constantly growing incisor teeth specialized for gnawing
         [syn: {gnawer}, {gnawing animal}]