determinative

/di-ˈtər-mə-ˌnā-tiv/

adjective

  1. having power or tendency to determine : tending to fix, settle, or define something

regard experiments as determinative of the principles from which deductions could be made

conclusive decisive determinative definitive mean bringing to an end. conclusive applies to reasoning or logical proof that puts an end to debate or questioning. decisive may apply to something that ends a controversy, a contest, or any uncertainty.