An Abrasion

1. The act of abrading, wearing, or rubbing off; the wearing away by friction. [First attested in the mid 17th century.][1]
2. (obsolete) The substance thus rubbed off; debris. [First attested in the mid 18th century.][1]
3. (geology) The effect of mechanical erosion of rock, especially a river bed, by rock fragments scratching and scraping it. [First attested in the mid 19th century.][1]
4. An abraded, scraped, or worn area. [First attested in the mid 20th century.][1]
5. (medicine) A superficial wound caused by scraping; an area of skin where the cells on the surface have been scraped or worn away. [First attested in the mid 20th century.][1]
6. (dentistry) The wearing away of the surface of the tooth by chewing.

Injury