Merriam-Webster Collegiate Dictionary - conclusive

 adjective  Date: 1536  1. of, relating to, or being a conclusion  2. putting an end to debate or question especially by reason of irrefutability  • ~ly adverb  • ~ness noun Synonyms:  ~, decisive, determinative, definitive mean bringing to an end. ~ applies to reasoning or logical proof that puts an end to debate or questioning ~ evidence. decisive may apply to something that ends a controversy, a contest, or any uncertainty a decisive battle. determinative adds an implication of giving a fixed character or direction the determinative factor in the court's decision. definitive applies to what is put forth as final and permanent the definitive biography.