What does "reef" mean?

Reef: (Mining.) A large vein of auriferous quartz; -- so called in Australia. Hence, any body of rock yielding valuable ore. Reef builder (Zoöl.), any stony coral which contributes material to the formation of coral reefs. -- Reef heron (Zoöl.), any heron of the genus Demigretta; as, the blue reef heron (D.jugularis) of Australia.

Additional senses

  1. 2.That part of a sail which is taken in or let out by means of the reef points, in order to adapt the size of the sail to the force of the wind. Note: From the head to the first reef-band, in square sails, is termed the first reef; from this to the next is the second reef; and so on. In fore-and-aft sails, which reef on the foot, the first reef is the lowest part. Totten. Close reef, the last reef that can be put in. -- Reef band. See Reef-band in the Vocabulary. -- Reef knot, the knot which is used in tying reef pointss. See Illust. under Knot. -- Reef line, a small rope formerly used to reef the courses by being passed spirally round the yard and through the holes of the reef. Totten. -- Reef pioints, pieces of small rope passing through the eyelet holes of a reef-band, and used reefing the sail. -- Reef tackle, a tackle by which the reef cringles, or rings, of a sail are hauled up to the yard for reefing. Totten. -- To take a reef in, to reduce the size of (a sail) by folding or rolling up a reef, and lashing it to the spar.
  2. 3.To reduce the extent of (as a sail) by roiling or folding a certain portion of it and making it fast to the yard or spar. Totten. To reef the paddles, to move the floats of a paddle wheel toward its center so that they will not dip so deeply.

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