Quiz: Remember the definition of mal de mer?
1580s, "apostate," probably (with change of suffix) from Spanish renegado, originally "Christian turned Muslim," from Medieval Latin renegatus, noun use of past participle of renegare "deny" (see renege). General sense of "turncoat" is from 1660s. The form renegate, directly from Medieval Latin, is attested in English from late 14c. As an adjective from 1705.