Definition
To do something in one fell swoop means to do it all at once or in a single action.
一举；一下子
She decided to tackle all the pending projects in one fell swoop.
她决定一次性处理所有待办项目。
The company laid off hundreds of employees in one fell swoop.
公司一次性裁员数百人。
I tried to get all the housework done in one fell swoop.
我试图一次性完成所有家务。