Open English Wordnet
Nouns
(n)reefa submerged ridge of rock or coral near the surface of the water (n)reefone of several strips across a sail that can be taken in or rolled up to lessen the area of the sail that is exposed to the wind Verbs
(v)reeflower and bring partially inboard“reef the sailboat's mast” (v)reefroll up (a portion of a sail) in order to reduce its area (v)reefreduce (a sail) by taking in a reef