reef

As a noun reef

is hoop (metal band on a barrel).

As an adjective reefy is

containing reefs.

As adjectives the difference between reef and reefal

is that reef is scabby; scurvy while reefal is of or pertaining to a reef.

As a noun reef

is the itch; any eruptive skin disorder.

As a verb reef

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

As nouns the difference between reef and phytoherm

is that reef is hoop (metal band on a barrel) while phytoherm is (geology|biology) a calcareous 'freshwater reef', generally built up from autochthonous petrification of bryophytes, funghi, algae and cyanobacteria.

In nautical terms the difference between reef and vigia

is that reef is to take in part of a sail in order to adapt the size of the sail to the force of the wind while vigia is a warning on a navigational chart indicating a possible reef or other hazard of unknown exact location.

As an adjective reef

is scabby; scurvy.

As a verb reef

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