verb (used with object), il·lus·trat·ed, il·lus·trat·ing.
verb (used without object), il·lus·trat·ed, il·lus·trat·ing.
Origin of illustrate
Word Origin for illustrate
1520s, "light up, shed light on;" 1610s, "educate by means of examples," back-formation from illustration, and in some cases from Latin illustratus, past participle of illustrare (see illustration). Sense of "provide pictures to explain or decorate" is 1630s. Related: Illustrated; illustrating.