Real Dictionary

lumpfish in American English
any of several sluggish, marine percoid fishes (family Cyclopteridae), esp. a large N Atlantic species (Cyclopterus lumpus), usually having a heavy body with hard spines, lumps, and a powerful ventral sucker
noun: any of several thick-bodied, sluggish fishes of the family Cyclopteridae, found in northern seas, having the pelvic fins modified and united into a sucking disk, esp Cyclopterus lumpus, of the North Atlantic

lumpfish in British English
noun: a North Atlantic scorpaenoid fish, Cyclopterus lumpus, having a globular body covered with tubercles, pelvic fins fused into a sucker, and an edible roe: family Cyclopteridae