green fish
/ˌɡriːn ˈfɪʃ/noun
1Fresh, unsalted fish; specifically cod (Gadus morrhua) before it has been salted or cured.
2 US. Any of several marine fishes found in American waters: (a) the bluefish, Pomatomus saltatrix (family Pomatomidae), found in most warm seas; (b) (more fully Alaska greenfish) the masked greenling, Hexagrammos octogrammus, which has green flesh; (c) the opaleye, Girella nigricans.
Origin
Late Middle English. From green + fish.