To reject or defeat something that has already been decided is called

Answer:
concede
Explanation:
according to ms. merriam-webster, the definition of concedeing is -
1.
admiting that something is true or valid after first denying or resisting it.
"I had to concede that I'd overreacted"
"he conceded defeat"
2.
surrender or yield (something that one possesses).
"to concede all the territory he'd won"
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