To take a reef in

Reef 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. [1913 Webster]

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. [1913 Webster]

{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. [1913 Webster]