The word "determinative" means something that determines or influences the outcome or result of a situation. It describes something that has the power to make a decision or settle something. Full definition
As a process theologian, of course, the fact that a doctrine is strongly supported in the Bible is not determinative of whether I accept it. (religion-online.org)
His ultimate answer is cast in terms of consequentialist moral reasoning, by which what counts as determinative in the moral argument is the outcome. (firstthings.com)
[64] Where theft by an employee is suspected the outcome of criminal charges is not determinative for employment purposes. (slaw.ca)