Reef

Part of speech: noun

Pronunciation: /ɹiːf/

Definitions

1. A submerged ridge or chain of rocks, often composed of coral, that provides habitat to marine life and can affect navigational conditions
2. A natural underwater structure formed primarily of coral or limestone that serves as a vital ecosystem for diverse aquatic organisms
3. A buildup of rock or coral in the ocean that can be hazardous for ships and supports a variety of marine species

Etymology: The most surprising link is with your ribs. The English noun "reef" descends from Old Norse "rif", meaning both "rib" and "reef", which means a sea-rock ridge was named after the same bone that protects your heart. Old Norse "rif" passed into Middle English as "rif" and was later reshaped into "reef", and it is a doublet of "rib", so the two English words are really the same word arriving by different routes. The sense of a rock ridge under water seems to have grown from the image of a rib-like line of stone rising from the sea floor. Dutch "rif", Low German "riff", and German "Riff" all borrowed the same Old Norse word, so the seafaring vocabulary of northern Europe shares a single Scandinavian source. A less certain second line of descent may connect the word to Old English "rift", meaning curtain or veil, or to an Old English verb meaning to uncoil or wind off. This pathway is not settled, so the rib origin remains the best-supported account.

Synonyms: coral reef, barrier reef, atoll