IPA: /ˈbaʊn.sɪŋ.li/
KK: /ˈbaʊn.sɪŋ.li/
In a manner that involves bouncing or jumping up and down.
The children played bouncingly on the trampoline, laughing with joy.
Bouncingly → It is formed from "bouncing" (the present participle of "bounce", which comes from Middle English "bouncen", meaning to rebound or spring back) and "-ly" (a suffix meaning in a manner of). The word "bouncingly" means in a manner that rebounds or springs back.
Think of something that moves in a lively way, like it is 'springing back' — that's what 'bouncingly' means.