1. (使)磨平;(使)磨光
If you wear something down or if it wears down, it becomes flatter or smoother as a result of constantly rubbing against something else.

2. 使斗志消磨;挫败
If you wear someone down, you make them gradually weaker or less determined until they eventually do what you want.

1. exhaust or get tired through overuse or great strain or stress

e.g. We wore ourselves out on this hike

Synonym: tirewear upontire outwearwearyjadewear outoutwearfag outfagfatigue

2. deteriorate through use or stress

e.g. The constant friction wore out the cloth

Synonym: wearwear offwear outwear thin