1. The process of wearing something away by friction or wear, or by scraping one object against another one: Dr. Kilfoil was concerned about the degree of detrition in Jackie's mouth and recommended that she wear a night guard for her teeth.
2. The act of attrition; such as, the wearing of stones by wind, water, or ice: Tammy and Tom collected some beautiful beach pebbles which were smoothed down by detritions.