1. A submerged ridge of rock or coral near the surface of the water
   "The ship narrowly avoided running aground on the coral reef"
    
2. One 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
   "The sailors quickly took in a reef as the wind picked up"

1. Lower and bring partially inboard
   "reef the sailing boat's mast"
    
2. Roll up (a portion of a sail) in order to reduce its area
   "The sailors reefed the mainsail as the wind increased"

1. A rocky region in the southern Transvaal in northeastern South Africa; contains rich gold deposits and coal and manganese
   - Witwatersrand, Rand

Derived forms: reefing, reefs, reefed

Type of: bring down, furl, get down, let down, lower, part, region, ridge, slip, strip, take down

Part of: canvas, sail, sheet, Transvaal, Transvaal Province

Encyclopedia: Reef