Something that is definitive provides a firm conclusion that cannot be questioned.
近义词
conclusive , absolute , definite
双语例句
例： No one has come up with a definitive answer as to why this should be so.
至于为什么该这样，还没有人想出确定的答案。
例： The study population was too small to reach any definitive conclusions.
被研究的人群太小，无法得出明确的结论。