ENLIGHTENMENT; Origin Middle English (in the sense ‘make luminous’; formerly also as inlighten ): in early use from Old English inlīhtan ‘to shine’; noun. 1. the action of enlightening or the state of being enlightened; 2. a European intellectual movement of the late 17th and 18th centuries emphasizing reason and individualism rather than tradition; It was heavily influenced by 17th-century philosophers such as Descartes, Locke, and Newton, and its prominent exponents include Kant, Goethe, Voltaire, Rousseau, and Adam Smith