DuckCorp Dico

Found one definition

1.                 From WordNet (r) 3.0 (2006):
                   
   
   
                   
                     
   reef
       n 1: a submerged ridge of rock or coral near the surface of the
            water
       2: a rocky region in the southern Transvaal in northeastern
          South Africa; contains rich gold deposits and coal and
          manganese [syn: Witwatersrand, Rand, Reef]
       3: 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
       v 1: lower and bring partially inboard; "reef the sailboat's
            mast"
       2: roll up (a portion of a sail) in order to reduce its area
       3: reduce (a sail) by taking in a reef