Physical or mental effort or activity directed toward the production or accomplishment of something.
예문
1. My mother worked herself ill. (어머니는 과로로 병이 나셨다) 2. water works (수도, 분수) 3. work oneself to death (과로로 죽다) 4. work at American history (미국 역사를 공부하다) 5. work one's employees hard (종업원을 혹사하다)
