wear away

Từ điển Oxford Advanced Learner 8th

ˌwear aˈway | ˌwear sthaˈway derived
to become, or make sth become, gradually thinner or smoother by continuously using or rubbing it
•The inscription on the coin had worn away.
•The steps had been worn away by the feet of thousands of pilgrims.
Main entry: ↑wear_derived