coun·ter·weight
noun/ˈkaʊntəweɪt/
/ˈkaʊntərweɪt/
(also counterbalance)
[usually singular]- counterweight (to something) a thing that has an equal but opposite effect to something else and can be used to limit the bad effects of something
平衡抵消物；平衡重（或块、锤） - The senate is the opposition’s counterweight to the new president.
参议院是反对派对新总统的制衡力量。
- The senate is the opposition’s counterweight to the new president.