abrasion          
noun  specialized uk/əˈbreɪ.ʒən/ us/əˈbreɪ.ʒən/
 [ U ] geology, engineering 磨损,磨耗;擦伤
the process of rubbing away the surface of something
  There seems to have been some abrasion of the surface. 表面好像有些磨损。 
  [ C ] medical (皮肤)擦伤处;(表层)磨损处
a place where the surface of something, such as skin, has been rubbed away
  She had a small abrasion on her knee. 她的膝盖擦伤了一小块。