grinding down
phrasal verbUK /ˈɡraɪndɪŋ daʊn/
US /ˈɡraɪndɪŋ daʊn/
Making something slowly become smaller, smoother, or weaker by rubbing it again and again.
The old machine kept grinding down the rocks into fine sand.
OTHER MEANINGS
2. Making someone feel tired, stressed, or hopeless over a long time.
The endless homework was grinding him down.
3. Slowly reducing or destroying something such as power or resistance.
The long strike was grinding down the company's profits.
4. Sharpening or smoothing a tool or surface by rubbing it.
He was grinding down the rough edge of the metal.