Word Origin & History
illustration
c.1375, "a spiritual illumination," from O.Fr. illustration, from L. illustrationem (nom. illustratio) "vivid representation" (in writing), lit. "an enlightening," from illustrare "light up, embellish, distinguish," from in- "in" + lustrare "make bright, illuminate." Mental sense of "act of making clear in the mind" is from 1581. Meaning "an illustrative picture" is from 1816. Illustrate "educate by means of examples," first recorded 1612. Sense of "provide pictures to explain or decorate" is 1638.