illustrate
v.
1520s, "light up, shed light on;" 1610s, "educate by means of examples," back-formation from illustration, and in some cases from Latin illustratus, past participle of illustrare (see illustration). Sense of "provide pictures to explain or decorate" is 1630s. Related: Illustrated; illustrating.
〔李〕[il-（in-）=on 在…上；lustrate=to light 照⇒“to light on sth. 照亮某物”→] v. make clear by stories，examples，etc. 说明，阐明
〔李〕[il-(in-);lustr;-atev.] v.（用图或例子）说明，例证 ←lustr (L lustrum)=puridication 净化