Definitions

1. noun

any of various large, powerful, bill-shaped fish, such as the marlin, sailfish, or swordfish, that are typically found in warm ocean waters and are prized by game fishermen

“He went deep-sea fishing to catch a billfish.”

2. noun

a fish with a prominent bill, such as a marlin or a swordfish, that is often associated with tropical or subtropical waters

“The billfish was a popular choice for seafood restaurants.”