abrasion

noun

1. (countable, uncountable)The act of abrading, wearing, or rubbing off; the wearing away by friction.

   “The metal surface showed signs of abrasion after years of use.”

2. (countable, uncountable)An act of abrasiveness.
3. (countable, obsolete, uncountable)The substance thus rubbed off; debris.
4. (countable, uncountable)The effect of mechanical erosion of rock, especially a river bed, by rock fragments scratching and scraping it.
5. (countable, uncountable)An abraded, scraped, or worn area.
6. (countable, uncountable)A superficial wound caused by scraping; an area of skin where the cells on the surface have been scraped or worn away.

   “The doctor cleaned the small skin abrasion on her knee.”

7. (countable, uncountable)The wearing away of the surface of the tooth by chewing.