reef reef /ˈriːf/

noun

1. () A submerged ridge of rock or coral near the surface of the water  ( reef )
   a submerged ridge of rock or coral near the surface of the water
     Snorkelers explored the vibrant coral reef, encountering a dazzling array of marine life.
   Snorkelers explored the vibrant coral reef, encountering a dazzling array of marine life.
   
   
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  ( reef )
   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
   

verb

1. Reduce (a sail) by taking in a reef  ( reef )
   reduce (a sail) by taking in a reef
   
2. Roll up (a portion of a sail) in order to reduce its area  ( reef )
   roll up (a portion of a sail) in order to reduce its area
   
3. Lower and bring partially inboard  ( reef )
   lower and bring partially inboard
    Reef the sailboat's mast
   reef the sailboat's mast
   

 Reef

noun

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