wear (sth) away
to become thin and disappear after repeated use or rubbing, or to cause something to become thin and disappear in this way （使）磨损，磨掉
In some diseases, the protective layer in a joint wears away.
to become thin and disappear after repeated use or rubbing, or to cause something to become thin and disappear in this way （使）磨损，磨掉
In some diseases, the protective layer in a joint wears away.