Meaning

noun a submerged ridge of rock or coral near the surface of the water

noun a rocky region in the southern Transvaal in northeastern South Africa; contains rich gold deposits and coal and manganese

noun one of several strips across a sail that can be taken in or rolled up to lessen the area of the sail that is exposed to the wind

originFrom Middle English ref, hreof, from Old English hrēof (“rough, scabby, leprous", also "a leper”), from Proto-Germanic *hreubaz (“rough, scabby, scrubby”), from Proto-Indo-European *kreup- (“scab, crust”), related to Old English hrēofla (“leprosy, leper”). Cognate with Scots reif (“a skin disease leaving crusts on the skin, the scab”), Old High German riob (“leprous, scabby, mangy”), Icelandic…

Etymology from Wiktionary, CC BY-SA 3.0