All 4 Uses

illustrate
in
Unbroken, by Hillenbrand
(Edited)

At Hamilton Field, an artist was working his way down the planes, painting each one's name and accompanying illustration.
p. 63.5 *

illustration = drawing
Kawamura brought a pencil and paper and began making drawings to illustrate things he wished to talk about.
p. 185.3

illustrate = help make clear
Right or wrong, Louie's suspicions illustrated how sensitive he was to the idea that he was unworthy of Cynthia.
p. 343.1 *

illustrated = helped make clear
Once, while Louie was out, she painted their dreary kitchen with elaborate illustrations of vines and animals, hoping to surprise him.
p. 365.2

illustrations = pictures

Definitions:

(1) (illustrate as in: as illustrated by this example)
to help make clear -- typically by example
(2) (illustrate as in: an illustrated children's book)
to draw pictures (or provide photographs) to accompany a book or other writing
(3) (meaning too rare to warrant focus)