Etymology
From Middle English inlighten, from Old English inlīhtan, inlȳhtan, inlēohtan (“to enlighten, light up”), from Proto-Germanic *inliuhtijaną (“to lighten, illuminate”), from Proto-Indo-European *leuk- (“to shine”), equivalent to in- + light. Cognate with Dutch inlichten (“to enlighten, inform”), Old High German inliuhten (“to enlighten, illuminate”), Gothic 𐌹𐌽𐌻𐌹𐌿𐌷𐍄𐌾𐌰𐌽 (inliuhtjan, “to enlighten, illuminate”). Compare also Middle English anlīhten, from Old English onlȳhtan (id.). More at in-, light.