The phrase "definitive evidence" refers to clear and unquestionable proof that supports or confirms a certain fact or conclusion. It means that there is strong, reliable, and absolute evidence that leaves no room for doubt. Full definition
All believers have to do to make atheists shut up, after admitting we are wrong, is to provide definitive evidence to support their claims. (religion.blogs.cnn.com)
Two studies — one in mice and the other in human subjects — offer the first definitive evidence that exercise alone can change the composition of microbes in the gut. (sciencedaily.com)
But I can not any longer believe in anything «supernatural» until some more definitive evidence can be presented. (religion.blogs.cnn.com)