objector

object +‎ -or

objector (plural objectors)

1. A person who objects to something.
   • 1925 July – 1926 May, A[rthur] Conan Doyle, “(please specify the chapter number)”, in The Land of Mist (eBook no. 0601351h.html), Australia: Project Gutenberg Australia, published April 2019:

     "It would be amusing, sir, to shut these various objectors up in a room and let them settle it among themselves."

• conscientious objector

• objection