From a Late Latin name that was derived from Latin serenus meaning “clear, tranquil, serene”. This name was borne by an obscure early saint. Edmund Spenser also used it in his poem The Faerie Queene (1590).
Latinized form of the Greek name Ἱπποκράτης (Hippokrates) meaning “horse power”, derived from the elements ἵππος (hippos) meaning “horse” and κράτος (kratos) meaning “power”. This was the name of a 5th-century BC Greek doctor who is known as the Father of Medicine.
From the Greek name Κοσμᾶς (Kosmas), which was derived from κόσμος (kosmos) meaning “order, decency”. Saint Cosmas was martyred with his twin brother Damian in the 4th century. They are the patron saints of physicians.