[il.lus.trate] vb -trat.ed ; -trat.ing [L illustratus, pp. of illustrare, fr. in- + lustrare to purify, make bright--more at luster] vt (1526) 1 obs a: enlighten b: to light up
2. a archaic: to make illustrious b obs (1): to make bright (2): adorn 3 a: to make clear: clarify b: to make clear by giving or by serving as an example or instance c: to provide with visual features intended to explain or decorate "~ a book"
4: to show clearly: demonstrate ~ vi: to give an example or instance -- il.lus.tra.tor n