noun

illustration

il-uh-STRAY-shuhn/ˌɪləˈstreɪʃn/

A concrete representation that makes an idea clearer.

The book's botanical illustration shows the features of the sunflower beside it.

Open book has a large carefully drawn botanical illustration of sunflower opposite blank ruled text-placeholder lines without writing; image clearly decorates and explains plant shown beside book.

Etymology

ilLatinin

+lustrLatinto illuminate

+ationLatinact or result

An illustration was literally an enlightening: light became an image for making something mentally clear. The name for that clarifying act came to designate a picture that performs it, including pictures used for decoration.

In context

Penguin Random House3:57

we're not saying we're using this exact illustration but this is what his work looks like and this is how it um fits with the style of the writing this was one of the early sketches

Inside Random House: "The Art of Cover Design"

More examples

The manual includes an illustration of each tool.
Her budget is a useful illustration of careful planning.
As an illustration, consider how a sponge absorbs water.

Forms

illustration · illustrations

illustrate verb — To explain with pictures or examples.

illustrator noun — A person who creates pictures for texts.

Similar words

diagram: A simplified drawing showing parts, relationships, or how something works.
example: A specific case used to explain, rather than necessarily a picture.