IPA: //ˈflɪkərɪŋli//
KK: /ˈflɪkərɪŋli/
In a way that involves quick, unsteady movements of light or flame.
The candle was flickeringly illuminating the dark room.
Flickeringly → It is formed from "flicker" (of uncertain origin, possibly imitative of the motion) and "-ingly" (a suffix used to form adverbs indicating manner). The word describes the manner in which something flickers, suggesting a quick, irregular movement of light.
Think of the word 'flicker' to remember that 'flickeringly' describes something that moves or shines in a quick, irregular way.