'ennoblement' originates from French and Latin via the verb 'ennoble', specifically from Old French 'enobler' (or Modern French 'ennoblir'), where the prefix 'en-' meant 'to make' and 'noble' derived from Latin 'nobilis' meant 'well-known, distinguished'.

'nobilis' in Latin became Old French 'noble', then the verb-form 'enobler/ennoblir' (to make noble) in Old/Middle French, which entered Middle English as 'ennoble'; the noun 'ennoblement' formed later by adding the '-ment' suffix to denote the action or result.

Initially it meant 'to make known or distinguished (to confer noble status)', and over time it has retained that core sense while also being used figuratively to mean 'to raise in dignity or moral worth'.