To give someone a noble title or rank, or to make someone or something more noble, dignified, or worthy in character.
From Old French 'ennobler', composed of 'en-' (to cause to be) + 'noble' (from Latin 'nobilis', meaning well-known, of high birth). The word entered English in the 15th century and has maintained both its literal (conferring titles) and figurative (elevating character) meanings.
Ennoble is one of those beautiful verbs that shows how adding 'en-' to an adjective can transform it into an action—Shakespeare used it to describe how virtue could 'ennoble' a person, turning an abstract quality into something you could actually do to someone.
Complete word intelligence in one call. Free tier — 50 lookups/day.