IPA: /ɪˈluːm/
KK: /ɪˈlum/
To make something bright or to light it up.
The streetlights illume the dark roads at night.
Past: illumined
Past Participle: illumined
Illume is derived from "in-" (meaning in or into) and "luminare" (meaning to light up or illuminate). The word refers to the act of bringing light into a space or making something bright.
Think of bringing light 'into' ('in-') a place, which helps you remember that 'illume' means to light up.