Learn That Word

Synonyms for Attrition (same or very similar meaning)

WordNet sense 1 (erosion by friction):
abrasion, corrasion, detrition

WordNet sense 2 (the wearing down of rock particles by friction due to water or wind or ice):

WordNet sense 3 (sorrow for sin arising from fear of damnation):
contriteness, contrition

From the ODE community, based on WordNetadd/edit