wear down phrasal verb ( see also ↑ wear )
1 . to gradually become flatter or smoother, or to make something become like this, because of rubbing or use:
My shoes have worn down at the heel.
wear something ↔ down
Its teeth were worn down.
2 . wear somebody ↔ down to gradually make someone physically weaker or less determined:
It was clear he was being worn down by the rumours over his future.