noun

1. the act or process of wearing away or grinding down by friction
2. any gradual wearing or weakening, esp. to the point of exhaustion a siege is a battle of attrition
3. loss of personnel in an organization in the normal course of events, as by retirement
4. Theol. repentance that is not perfect because not prompted solely by sorrow for having offended God

Etymology: ME attricioun < L attritio < attritus, pp. of atterere, to wear, rub away < ad-, to + terere, to rub: see throw