sailfish

noun, plural (especially collectively) sail·fish, (especially referring to two or more kinds or species) sail·fish·es.

1. a large tropical and subtropical marine fish, Istiophorus platypterus, of the family Istiophoridae, distinguished by a long, high dorsal fin, long pelvic fins, and a double keel on each side of the tail.
2. any of several related fishes having a high dorsal fin.

noun plural -fish or -fishes

1. any of several large scombroid game fishes of the genus Istiophorus, such as I. albicans (Atlantic sailfish), of warm and tropical seas: family Istiophoridae. They have an elongated upper jaw and a long sail-like dorsal fin
2. another name for basking shark