reef (1), riff (1)

[Dut. rif; cogn. with Icel. rif =a reef, rif a =a rift, a crack; Dan. rev =a reef, revne to crack; Ger. riff.] 1. A chain or range of rocks in the ocean, lying at or near the surface of the water. "How far the principal or outer reef extends toward the north."-Cook: First Voyage, bk. iii., ch. v 2. A name given by Australian miners to a gold bearing quartz vein.