Source : Webster's Revised Unabridged Dictionary (1913)

Proboscis \Pro*bos"cis\, n.; pl. {Proboscides}. [L. fr. Gr. ?; ?
   before + ? to feed, graze.]
   1. (Zo["o]l.) A hollow organ or tube attached to the head, or
      connected with the mouth, of various animals, and
      generally used in taking food or drink; a snout; a trunk.

   Note: The proboscis of an elephant is a flexible muscular
         elongation of the nose. The proboscis of insects is
         usually a chitinous tube formed by the modified
         maxill[ae], or by the labium. See Illusts. of
         {Hemiptera} and {Lepidoptera}.

   2. (Zo["o]l.) By extension, applied to various tubelike mouth
      organs of the lower animals that can be everted or
      protruded.

   Note: The proboscis of annelids and of mollusks is usually a
         portion of the pharynx that can be everted or
         protruded. That of nemerteans is a special long
         internal organ, not connected with the mouth, and not
         used in feeding, but capable of being protruded from a
         pore in the head. See Illust. in Appendix.

   3. The nose. [Jocose]

   {Proboscis monkey}. (Zo["o]l.) See {Kahau}.

Source : WordNet®

proboscis
     n 1: the human nose (especially when it is large)
     2: a long flexible snout as of an elephant [syn: {trunk}]
     [also: {proboscides} (pl)]