The Collaborative International Dictionary of English v.0.48:

Kahau \Ka*hau"\, n. [Native name, from its cry.] (Zool.)
   A long-nosed monkey (Nasalis larvatus, formerly
   Semnopithecus nasalis), native of Borneo. The general color
   of the body is bright chestnut, with the under parts,
   shoulders, and sides of the head, golden yellow, and the top
   of the head and upper part of the back brown. Called also
   proboscis monkey. It is now an endangered species. [Written
   also kaha.]
   [1913 Webster +PJC]

The Collaborative International Dictionary of English v.0.48:

Proboscis \Pro*bos"cis\, n.; pl. Proboscides. [L. fr. Gr. ?; ?
   before + ? to feed, graze.]
   1. (Zool.) 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.
      [1913 Webster]

   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.
         [1913 Webster]

   2. (Zool.) By extension, applied to various tubelike mouth
      organs of the lower animals that can be everted or
      protruded.
      [1913 Webster]

   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.
         [1913 Webster]

   3. The nose. [Jocose]
      [1913 Webster]

   Proboscis monkey. (Zool.) See Kahau.
      [1913 Webster]

WordNet (r) 3.0 (2006):

proboscis monkey
    n 1: Borneo monkey having a long bulbous nose [syn: proboscis
         monkey, Nasalis larvatus]