Of Germanic origin, derived from the Old High German vocabulary word eornost ‘serious business, battle to the death’. The name was introduced into England in the 18th century by followers of the Elector of Hanover, who became George I of England. A variant spelling, Earnest, has arisen by association with the modern English adjective earnest.
Spanish and Catalan: from the personal name Nabor, which was borne by a saint believed to have been martyred in Milan in the 4th century, about whom nothing else is known. The personal name is probably a derivative of Hebrew barar ‘to choose’, ‘to purify’, which evolved into nabar ‘honest’, ‘ernest’, ‘clean’.