The Collaborative International Dictionary of English v.0.48:

Pomfret \Pom"fret\, n. [Perhaps corrupt. fr. Pg. pampano a kind
   of fish.] (Zool.)
   (a) One of two or more species of marine food fishes of the
       genus Stromateus (Stromateus niger, Stromateus
       argenteus) native of Southern Europe and Asia.
   (b) A marine food fish of Bermuda (Brama Raji).
       [1913 Webster]

WordNet (r) 3.0 (2006):

pomfret
    n 1: deep-bodied sooty-black pelagic spiny-finned fish of the
         northern Atlantic and northern Pacific; valued for food
         [syn: pomfret, Brama raii]