This is the 2862nd most frequent French word.
décisif
Decisive; conclusive or determining.
In this sentence, 'décisive' is used as an adjective to describe the impact of a decision, meaning 'crucial' or 'determining' in the context of the situation.
Sa décision a été décisive pour le succès du projet.
His decision was crucial for the project's success.
Here, 'décisif' is used to characterize the necessity or importance of prompt action.
Il est décisif d'agir rapidement dans cette situation.
It is crucial to act quickly in this situation.
In this example, 'décisif' describes the match as being determining or pivotal in the outcome of a situation.