The term 'wearing down' can be described by four crossword solutions: ABRADING (8 letters), EROSION (7 letters), ATTRITION (9 letters), and EROSIVE (7 letters). ABRADING is the process of rubbing away a surface by friction, usually with a tool or abrasive material. EROSION is the gradual destruction of something, typically land, by natural processes such as wind or water. ATTRITION is the gradual reduction of something through sustained effort or pressure. Finally, EROSIVE is an adjective that describes something that causes EROSION.