Source : Webster's Revised Unabridged Dictionary (1913)

Nares \Na"res\, n. pl. [L., pl. of naris nostril.] (Anat.)
   The nostrils or nasal openings, -- the anterior nares being
   the external or proper nostrils, and the posterior nares, the
   openings of the nasal cavities into the mouth or pharynx.

Source : WordNet®

naris
     n : any of the openings to the nasal cavities that allow air to
         flow through the cavities to the pharynx
     [also: {nares} (pl)]

nares
     See {naris}