reef1

[reef] /rif/
noun
1.
a ridge of rocks or sand, often of coral debris, at or near the surface of the water.
2.
Mining. a lode or vein.
Origin
1575-85; earlier riff(e) < Dutch rif

reef2

[reef] /rif/
noun
1.
a part of a sail that is rolled and tied down to reduce the area exposed to the wind.
verb (used with object)
2.
to shorten (sail) by tying in one or more reefs.
3.
to reduce the length of (a topmast, a bowsprit, etc.), as by lowering, sliding inboard, or the like.
4.
to pull (old oakum) out of seams, as with a rave hook (often followed by out).
Origin
1350-1400; Middle English refe (noun) < Dutch reef
Related forms
unreefed, adjective
Examples from the web for reef
  • In a single day the anchor of a cruise ship can destroy an area of coral reef half the size of a football pitch.
  • Coral reef team with a mind-boggling array of life in waters that are often nutrient poor.
  • During coral growth, these elements are incorporated into the reef skeleton in varying amounts.
  • Certain sea creatures tint their skin with pigments from the corals they've eaten to take on the color of their home reef.
  • Seen in the right light, yellow reef fish become spotty pains in the tail fin.
  • When looking for first homes, reef fish tend toward noisy reefs, new experiments show.
  • Overfishing and reef destruction almost eliminated large fish, then medium-sized fish, finally leaving only the small ones.
  • So stressed middle-sized fish make for both happy coral and happy predators-in short, a healthy and highly productive reef.
  • In contrast, even beach umbrellas survived the milder surge along an adjacent beach where the reef was still intact.
  • Oriskany is the largest warship ever to be intentionally sunk as an artificial coral reef.
British Dictionary definitions for reef

reef1

/riːf/
noun
1.
a ridge of rock, sand, coral, etc, the top of which lies close to the surface of the sea
2.
a ridge- or mound-like structure built by sedentary calcareous organisms (esp corals) and consisting mainly of their remains
3.
a vein of ore, esp one of gold-bearing quartz
Word Origin
C16: from Middle Dutch ref, from Old Norse rifrib1, reef²

reef2

/riːf/
noun
1.
the part gathered in when sail area is reduced, as in a high wind
verb
2.
to reduce the area of (sail) by taking in a reef
3.
(transitive) to shorten or bring inboard (a spar)
Word Origin
C14: from Middle Dutch rif; related to Old Norse rif reef, rib1, German reffen to reef; see reef1

Reef

/riːf/
noun the Reef
1.
another name for the Great Barrier Reef
2.
another name for the Witwatersrand
Word Origin and History for reef
n.

"rock ridge underwater," 1580s, riffe, probably via Dutch riffe, from a Scandinavian source, cf. Old Norse rif "ridge in the sea; reef in a sail," literally "rib" (see rib (n.)).

"horizontal section of sail," late 14c. (mid-14c. in rif-rope), from a Scandinavian source, cf. Old Norse rif "reef of a sail," probably a transferred use of rif "ridge under the sea; rib" (see rib (n.) and cf. reef (n.1)). German reff, Swedish ref, Norwegian riv, Danish reb likely all are from the Old Norse word.

v.

1660s, "take in, roll up" (as a sail on a ship), from reef (n.2). Related: Reefed; reefing.

reef in Science
reef
  (rēf)   
A strip or ridge of rocks, sand, or coral that rises to or near the surface of a body of water. See more at coral reef.