illuminate (v.)

c. 1500, "to light up, shine on," a back-formation from illumination or else from Latin illuminatus, past participle of illuminare "light up, make light, illuminate." Earlier was enlumyen (late 14c.) "decorate written material by hand with gold, silver, or bright colors," from Old French enluminer, from Late Latin inluminare; also illumine (late 14c.). Related: Illuminated; illuminating; illuminable.