wear down | ˌwear sth ↔ ˈdown
to become, or make sth become, gradually smaller or smoother by continuously using or rubbing it :
Notice how the tread on this tyre has worn down.
wear down | ˌwear sth ↔ ˈdown
to become, or make sth become, gradually smaller or smoother by continuously using or rubbing it :
Notice how the tread on this tyre has worn down.
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005