Source : Webster's Revised Unabridged Dictionary (1913)

Tentaculum \Ten*tac"u*lum\, n.; pl. {Tentacula}. [NL. See
   {Tentacle}.]
   1. (Zo["o]l.) A tentacle.

   2. (Anat.) One of the stiff hairs situated about the mouth,
      or on the face, of many animals, and supposed to be
      tactile organs; a tactile hair.