attrition[əˈtrɪʃn]：n.(尤指给敌人造成的)削弱，消耗；人员减缩；人员流失 

例句：The company plans to cut a quarter of its workforce over six years through natural attrition and fewer hirings.

句意：公司计划在6年内通过人员自然流失和减少雇用使员工总数减少1/4。