Reef

Source : Admiral W H Smyth - The Sailor's Wordbook

REEF. A certain portion of a sail comprehended between the head of a sail and any of the reef-bands. The intention of each reef is to reduce the sail in proportion to the increase of the wind; there are also reefs parallel to the foot or bottom of large sails, extended upon booms.—Close-reefed is when all the reefs of the top-sails are taken in . —Reef is also a group or continuous chain of rocks, sufficiently near the surface of the water to occasion its breaking over them. (See FRINGING-REEFS and BARRIER-REEFS.)