coral:  Coral may ultimately be of Semitic origin (Hebrew gōrāl ‘pebble’ has been compared), but the first record we have of it is as Greek korállion, which came to English via Latin corallum or corallium and Old French coral. Until the 17th century, the word was applied exclusively to the red coral (Corallium nobile); hence its use, since the early 16th century, for a ‘rich red colour’.
c. 1300, from Old French coral (12c., Modern French corail), from Latin corallium, from Greek korallion; perhaps of Semitic origin (compare Hebrew goral "small pebble," Arabic garal "small stone"), originally just the red variety found in the Mediterranean, hence use of the word as a symbol of "red." Related: Coralline. Coral snake (1760) is so called for the red zones in its markings. Coral reef is attested from 1745.