Reef /(rēf)/

Reef

A chain or range of rocks lying at or near the surface of the water. See Coral reefs, under Coral.
A large vein of auriferous quartz; -- so called in Australia. Hence, any body of rock yielding valuable ore. (Mining.)

Reef builder: any stony coral which contributes material to the formation of coral reefs.
Reef heron: any heron of the genus Demigretta; as, the blue reef heron (Demigretta jugularis) of Australia.

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. (Naut.)

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.
Reef points: 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.
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.

v. t.

imp. & p. p. Reefed; p. pr. & vb. n. Reefing

To reduce the extent of (as a sail) by rolling or folding a certain portion of it and making it fast to the yard or spar. (Naut.)

To reef the paddles: to move the floats of a paddle wheel toward its center so that they will not dip so deeply.