The Collaborative International Dictionary of English v.0.48:

Haddock \Had"dock\ (-d[u^]k), n. [OE. hadok, haddok, of unknown
   origin; cf. Ir. codog, Gael. adag, F. hadot.] (Zool.)
   A marine food fish (Melanogrammus [ae]glefinus), allied to
   the cod, inhabiting the northern coasts of Europe and
   America. It has a dark lateral line and a black spot on each
   side of the body, just back of the gills. Galled also
   haddie, and dickie.
   [1913 Webster]

   Norway haddock, a marine edible fish (Sebastes marinus)
      of Northern Europe and America. See Rose fish.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Rosefish \Rose"fish`\, n. (Zool.)
   A large marine scorpaenoid food fish (Sebastes marinus)
   found on the northern coasts of Europe and America. called
   also red perch, hemdurgan, Norway haddok, and also,
   erroneously, snapper, bream, and bergylt.
   [1913 Webster]

   Note: When full grown it is usually bright rose-red or
         orange-red; the young are usually mottled with red and
         ducky brown.
         [1913 Webster]