Reef, n. [Akin to D. reef, G. reff, Sw. ref; cf. Icel. rif reef, rifa to basten together. Cf. Reeve, v. t., River.] (Naut.) 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.
☞ 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 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. 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.