Noun; Word used by sport-fisherman to describe an enormous catch. A boss fish is usually at the top of the food-chain, meaning that there is no other fish in the area that would dare contend with it. When a fish slams on an angler's line and it is clear that the animal is not an ordinary fish, it is obvious that the fish is a boss. On occasion, the fish comes in slowly and it is unclear whether or not the fish is a boss. Once the fish is actually witnesses, it can be determined if it is a boss.
If your line gets slammed by a fish and it is instantly clear that it's a monster, you can vocally declare, "Hell yea! It's a boss!" This can be assigned to any species as long as the animal is extraordinarily large for it's species. Example: Boss-Bass, Boss-Pike, Boss-Walleye, etc.