conceder
/kɒnˈsɛdər/Definitions
1. verb
to acknowledge or admit (something) to be true, valid, or correct; to yield or surrender (a claim or position)
“The politician was forced to concede the election to her opponent.”
2. noun
a person who concedes or admits (something) to be true, valid, or correct
“The conceder of the award was not present at the ceremony.”