What is the meaning of Reef?

A chain or range of rocks, sand, or coral lying at or near the surface of the water.

A large vein of auriferous quartz; hence, any body of rock yielding valuable ore.

A portion of a sail rolled and tied down to lessen the area exposed in a high wind.

A reef knot.

To take in part of a sail in order to adapt the size of the sail to the force of the wind.

To pull or yank strongly, especially in relation to horse riding.

To move the floats of a paddle wheel toward its center so that they will not dip so deeply.

To manipulate the lining of a person's pocket in order to steal the contents unnoticed.

Scabby; scurvy.

The itch; any eruptive skin disorder.

Dandruff.

line drawn on the ground, furrow

Alternative form of reef (shallows; strip of sail)

Source: wiktionary.org