As a noun:
* The textbook was filled with helpful illustrations of anatomical structures.
* The artist's work was a powerful illustration of the human condition.
* Her speech provided a vivid illustration of the challenges facing our community.
As a verb:
* The speaker illustrated her point with a compelling anecdote.
* The website illustrates the company's commitment to sustainability.
* The artist illustrated the book with beautiful drawings.
In a more figurative sense:
* The recent economic downturn is a stark illustration of the fragility of the global market.
* His actions were a perfect illustration of his lack of empathy.
Let me know if you'd like more examples or have a specific context in mind!