反発
はんぱつ · hanpatsu · JLPT N1 · noun
rebound
🏓 はんぱつ sounds like 'hang-pat': a ping-pong ball rebounds off the paddle, a rebound is a repelling bounce back
反 means against or back, 発 means launch or emit. Together they describe something launched back against a force: a rebound, repelling, opposing.
反 — hand 又 under cliff 厂
Originally a pictograph of a hand (又) turning something over against a cliff or slope (厂), depicting the action of flipping or reversing. From this came the core meaning 'to turn over,' which extended to 'opposite,' 'contrary,' and 'rebel against.' The character is purely semantic, with no phonetic component.