Pulverized into tiny pieces; shattered to bits. Also used figuratively to mean completely ruined.
皿を落として粉々に割ってしまった。
I dropped the plate and shattered it into pieces.
窓ガラスが衝撃で粉々になった。
The window glass was smashed into tiny fragments by the impact.
その失敗で彼の計画は粉々になった。
That failure completely ruined his plan.