n. any of several large carplike North American fish.n. Any of several large fresh-water fishes of the family Catostomidæ (also called suckers see Sucker family), of the Mississippi valley. The red-mouthed or brown (Ictiobus bubalus), the big-mouthed buffalofish (Ictiobus cyrinellus, formerly called Bubalichthys urus), the black buffalofish (Ictiobus niger), and the small-mouthed buffalofish (Ictiobus bubalus, formerly called Bubalichthys altus), are among the more important species used as food.