1. Any long, round-bodied fish (family Eleotridae) with a blunt head, eyes located almost directly above the jaws, two dorsal fins, and a rounded tail fin, found in marine, brackish, or fresh water. There are many species.

2. The common name for a variety of unrelated species of small, mostly bottom-dwelling, freshwater fish.

3. A short, hollow cylinder into which a solid rod (a pintle) fits to form a type of hinge.