/ə'trɪʃn; ə`trɪʃən/
n [U]
1 process of gradually weakening sb's strength and confidence by continuous harassment (used esp in the expression shown) 消耗, 消损（尤用于以下示例）
*a war of attrition 消耗战.
2 wearing sth away by rubbing; friction 磨损; 摩擦.

n[U]formal
[Date: 1400-1500; Language: Latin;Origin: attritio, from atterere 'to rub against', from ad- 'to' + terere 'to rub']
the process of gradually destroying your enemy or making them weak by attacking them continuously
　a war of attrition
especially AmE when people leave a company or course of study and are not replaced
　Staff reductions could be achieved through attrition and early retirements.