defeasance
1. defeasance clause
契约中的废止条款
2. deed of defeasance
毁约证书
3. The court held that Congress had intended vested rights under the lease to be invulnerable to defeasance by subsequently issued regulations
法院认为,国会在立法时的意图是,租约赋予的权利不能因其后颁布的条例而作废。