conclusive, decisive, determinative, definitive mean bringing to an end. conclusive applies to reasoning or logical proof that puts an end to debate or questioning.

DECISIVE definition: having the power or quality of deciding; putting an end to controversy; crucial or most important. See examples of decisive used in a sentence.

1. Settling a matter or conflict; conclusive: the decisive battle in the war; the decisive piece of evidence in the lawsuit. 2. Characterized by or showing the ability to make decisions quickly and firmly; …

DECISIVE definition: 1. able to make decisions quickly and confidently, or showing this quality: 2. strongly affecting…. Learn more.

Jan 20, 2026 · decisive (comparative more decisive, superlative most decisive) Having the power or quality of deciding a question or controversy; putting an end to contest or controversy; final; conclusive.

Factsheet What does the word decisive mean? There are five meanings listed in OED's entry for the word decisive. See ‘Meaning & use’ for definitions, usage, and quotation evidence.

de•ci•sive /dɪˈsaɪsɪv/ adj. having the power to decide: The decisive argument was the savings his plan would bring. displaying firmness; resolute: a decisive manner. unquestionable; definite: a decisive …

Definition of decisive. English dictionary and integrated thesaurus for learners, writers, teachers, and students with advanced, intermediate, and beginner levels.

If you make decisions quickly, you are someone who is decisive. A decisive event can settle something, like a war. People who are wishy-washy are the opposite of decisive: being decisive means you don't …

Having the power or quality of deciding a question or controversy; putting an end to contest or controversy; final; conclusive. A decisive battle is fatal for one side's war chances.