This is the 1802nd most frequent French word.
décisive
Determining or having the power to decide an outcome; crucial.
Here, 'décisive' describes a victory that is crucial or conclusive in determining the outcome.
La victoire décisive de l'équipe a marqué un tournant dans la compétition.
The team's decisive victory marked a turning point in the competition.
In this sentence, 'décisif' is used to indicate that his role was of critical importance.
Son rôle a été décisif pour le succès du projet.
His role was decisive for the project's success.
Here, 'décisive' qualifies the decision, emphasizing its importance and definitive nature in addressing the matter.