Webster's Revised Unabridged Dictionary · 1913

Conclusive

Conclusive , adjective

[Compare French conclusif.]

Belonging to a close or termination; decisive; convincing; putting an end to debate or question; leading to, or involving, a conclusion or decision.
Secret reasons... equally conclusive for us as they were for them. — Rogers
Collocations (2)
Conclusive evidence (Law) , that of which, from its nature, the law allows no contradiction or explanation.
Conclusive presumption (Law) , an inference which the law makes so peremptorily that it will not allow it to be overthrown by any contrary proof, however strong.