Meaning

noun lean white flesh of fish similar to but smaller than cod; usually baked or poached or as fillets sauteed or fried

noun important food fish on both sides of the Atlantic; related to cod but usually smaller

originFrom Middle English haddok. Compare Anglo-Norman hadoc from Old French hadot, probably from an English source. Further origin uncertain, but hadot could have evolved from (h)adoux, (h)adoz, from adoub, from adouber, adober (“to prepare”), cognate with Italian addobbare (“to souse fish or meat”). The spelling is usually regarded as a diminutive in -ok (see -ock).

Etymology from Wiktionary, CC BY-SA 3.0