definitive
adjective uk/dɪˈfɪn.ɪ.tɪv/ us/dɪˈfɪn.ə.t̬ɪv/
C2 最终的，决定性的;不可更改的
not able to be changed or improved
a definitive judgment/ruling 最终的判决
There are no definitive answers/solutions to this problem. 这个问题没有决定性的答案/彻底的解决办法。
The police have no definitive proof of her guilt. 警察并未掌握她犯罪的确凿证据。
最佳的;最完整可靠的
considered to be the best of its type
He's written the definitive guide to Thailand. 他写出了最完整可靠的泰国旅游指南。