The Collaborative International Dictionary of English v.0.48:

Rhino \Rhi*no\, n. [Etymol. uncertain.]
   Gold and silver, or money. [Cant] --W. Wagstaffe.
   [1913 Webster]

         As long as the rhino lasted.             --Marryat.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Rhino- \Rhi"no-\
   A combining form from Greek ??, ???, the nose, as in
   rhinolith, rhinology.
   [1913 Webster] Rhinocerial

WordNet (r) 3.0 (2006):

rhino
    n 1: massive powerful herbivorous odd-toed ungulate of southeast
         Asia and Africa having very thick skin and one or two horns
         on the snout [syn: rhinoceros, rhino]