/ ˌɪləˈstreɪʃn; NAmE / noun
1.
[ C ] a drawing or picture in a book, magazine, etc. especially one that explains sth :
50 full-colour illustrations
➡ note at picture
2.
[ U ] the process of illustrating sth :
the art of book illustration
3.
[ C , U ] a story, an event or an example that clearly shows the truth about sth :
The statistics are a clear illustration of the point I am trying to make
Let me, by way of illustration , quote from one of her poems.
➡ note at example
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WORD ORIGIN
late Middle English (in the sense illumination; spiritual or intellectual enlightenment ): via Old French from Latin illustratio(n-) , from the verb illustrare , from in- upon + lustrare illuminate.