ぼつぼつ
ぼつぼつ · botsubotsu · JLPT N1 · noun
gradually
🌦️ ぼつぼつ sounds like 'bottle-bottle': dots of rain tapping, one drop at a time, here and there.
Reduplicated ぼつ (a dot or spot, from 没/ぼつ 'sunk') doubled into ぼつぼつ. Repetition marks scattered, gradual events, like spots of rain starting to fall.