attrition
Pronunciation: /əˈtrɪʃ(ə)n/
noun
- 1the process of reducing something’s strength or effectiveness through sustained attack or pressure: the council is trying to wear down the opposition by attrition the squadron suffered severe attrition of its bombers
- chiefly North American & Australian/NZ the gradual reduction of a workforce by employees leaving and not being replaced rather than by redundancy: the company said that it will reduce its worldwide employment by about 10% through attrition
- wearing away by friction; abrasion: the skull shows attrition of the edges of the teeth

Origin:
late Middle English (in attrition (sense 2)): from late Latin attritio(n-), from atterere 'to rub'