The term 'reef fish' refers to a variety of fish that inhabit coral reefs. One example of a reef fish is the groper, which is a six-letter word. Groper is a type of fish that lives in shallow waters near coral reefs. It is usually found in tropical and subtropical regions, and it feeds on crustaceans, mollusks, and other small fish. Groper can grow up to two meters in length and can weigh up to 45 kilograms.