The Collaborative International Dictionary of English v.0.48:

Vibrissa \Vi*bris"sa\, n.; pl. Vibrissae. [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.
      [1913 Webster]

   2. (Zool.) The bristlelike feathers near the mouth of many
      birds.
      [1913 Webster]

WordNet (r) 3.0 (2006):

vibrissa
    n 1: a long stiff hair growing from the snout or brow of most
         mammals as e.g. a cat [syn: whisker, vibrissa, sensory
         hair]