The Collaborative International Dictionary of English v.0.48:
Reef \Reef\ (r[=e]f), n. [Akin to D. rif, G. riff, Icel. rif,
Dan. rev; cf. Icel. rifa rift, rent, fissure, rifa to rive,
bear. Cf. Rift, Rive.]
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
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