Source : Webster's Revised Unabridged Dictionary (1913)

Vibrissa \Vi*bris"sa\, n.; pl. {Vibriss[ae]}. [L. vibrissae,
   pl., the hairs in the nostrils of man, fr. vibrare to
   vibrate; -- so called because touching them tickles a person,
   and causes him to shake his head.]
   1. (Anat.) One of the specialized or tactile hairs which grow
      about the nostrils, or on other parts of the face, in many
      animals, as the so-called whiskers of the cat, and the
      hairs of the nostrils of man.

   2. (Zo["o]l.) The bristlelike feathers near the mouth of many
      birds.

Source : WordNet®

vibrissa
     n : a long stiff hair growing from the snout or brow of most
         mammals as e.g. a cat [syn: {whisker}, {sensory hair}]
     [also: {vibrissae} (pl)]