Enlighten, v. t. — Webster enters it under “enlighten”
Etymology: [Pref. en- + lighten: cf. AS. inlihtan. Cf. Enlight.]
1. To supply with light; to illuminate; as, the sun enlightens the earth. His lightnings enlightened the world. Ps. xcvii. 4.
2. To make clear to the intellect or conscience; to shed the light of truth and knowledge upon; to furnish with increase of knowledge; to instruct; as, to enlighten the mind or understanding. The conscience enlightened by the Word and Spirit of God. Trench.
Shades of meaning
Fernald lists enlightened only as an antonym, under brutish.
He lists it without comment; the entries above explain its neighbors.
Synonyms
none given