n. An elasmobranchiate or selachian fish of the family Pristidæ, having the snout prolonged into a flat saw or serra beset on each side with horizontal teeth pointing sidewise.n. Hence also By extension, one of the different selachians of the family Pristiophoridæ, 337 having a similar saw-like appendage, which never reaches such a size as in the Pristidæ, or true saw-fishes. They are confined to the Pacific. See cut under Pristiophorus.