/ˈɪl.ə.streɪt/
to make the meaning of sth clearer by using examples, pictures, etc. （用示例、图画等）说明，解释
~ sth
To illustrate my point, let me tell you a little story.
为了说明我的观点，让我来给你们讲个小故事。
Last year’s sales figures are illustrated in Figure 2.
图 2 显示了去年的销售数字。
~ how, what, etc.…
Here’s an example to illustrate what I mean.
这儿有个例子可以说明我的意思。