The Collaborative International Dictionary of English v.0.48:

Guffer \Guf"fer\, n. (Zool.)
   The eelpout; guffer eel.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Eelpout \Eel"pout`\, n. [AS. ?lepute.] (Zo["o]l.)
   (a) A European fish (Zoarces viviparus), remarkable for
       producing living young; -- called also greenbone,
       guffer, bard, and Maroona eel. Also, an American
       species (Z. anguillaris), -- called also mutton fish,
       and, erroneously, congo eel, ling, and lamper eel.
       Both are edible, but of little value.
   (b) A fresh-water fish, the burbot.
       [1913 Webster]