- de|ci|sive [ dı`saısıv ] adjective **1. ) making the final result of a situation completely certain:Gettysburg, site of the final, decisive battle of the Civil WarCleveland's reputation for reliability was the decisive factor in winning the contract.The U.S. has played a decisive role in these negotiations.2. ) able to make choices or decide what to do quickly and confidently:As a chairperson, he was firm and decisive.a ) used about someone's behavior:decisive action: We must take decisive action to solve this problem.3. ) a decisive victory or defeat is one in which the winner does much better than the LOSER:a decisive victory for the Democratic Party╾ de|ci|sive|ly adverb╾ de|ci|sive|ness noun uncount
Usage of the words and phrases in modern English. 2013.