n. [ Named after R. J. L. Guppy, who brought speciments to the British museum. RHUD ] A small freshwater fish of South America and West Indies (Lebistes reticulatus or Poecilia reticulata, originaly called Gerardinus guppyi), often kept in aquariums; also called rainbow fish.
Syn. -- rainbow fish, Lebistes reticulatus. [ WordNet 1.5 ]