snook / snoŏk/ • n. a large edible game fish (Centropomus undecimalis, family Centropomidae) of the Caribbean that is sometimes found in brackish water. snook2 • n. (in phrase cock a snook) inf., chiefly Brit. place one's hand so that the thumb touches one's nose and the fingers are spread out, in order to express contempt: you wouldn't be so quick to cock a snook if she were actually looking at you. ∎ fig. openly show contempt or a lack of respect for someone or something; thumb one's nose: he spent a lifetime cocking a snook at the art world.