[1] : The Collaborative International Dictionary of English v.0.48

haddock \had"dock\ -du^k, n. oe. hadok, haddok, of unknown
   origin; cf. ir. codog, gael. adag, f. hadot. zool.
   a marine food fish melanogrammus aeglefinus, 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
see also:
melanogrammus aeglefinus haddie dickie norway haddock sebastes marinus rose fish 

[2] : WordNet (r) 2.0

haddock
     n 1: lean white flesh of fish similar to but smaller than cod;
          usually baked or poached or as fillets sauteed or fried
     2: important food fish on both sides of the atlantic; related
        to cod but usually smaller syn: melanogrammus aeglefinus
see also:
melanogrammus aeglefinus 

[3] : U.S. Gazetteer (1990)

haddock, ga
  zip codes: 31033

Haddock >> H Words
Haddock, definition of term: Haddock
haddock_pag1.html

Finnan Haddock >> F Words
Finnan Haddock, definition of term: Finnan Haddock
finnan+haddock_pag1.html