defeasance
/dɪˈfiːzəns/noun
mass noun
1- Law the action or process of rendering something null and void【律】废止。
1.1
- count noun a clause or condition which, if fulfilled, renders a deed or contract null and void契约废止条款。
词源
late Middle English (as a legal term)： from Old French defesance, from defaire, desfaire 'undo' （see DEFEAT）.