[seyl-fish] 
) -fish, (especially referring to two or more kinds or species) -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. |
| sail·fish (sāl'fĭsh') n. pl. sailfish or sail·fish·es Any of various large marine fishes of the genus Istiophorus, having a large saillike dorsal fin and an upper jaw that is prolonged into a spearlike bone. |