1. A chain or range of rocks lying at or near the surface of the water. See Coral reefs, under Coral.
2. Mining. A large vein of auriferous quartz; -- so called in Australia. Hence, any body of rock yielding valuable ore.
Reef builder Zool., any stony coral which contributes material to the formation of coral reefs.
Reef heron Zool., any heron of the genus Demigretta; as, the blue reef heron (Demigretta jugularis) of Australia.