This is the 7259th most frequent Dutch word.
beslissend
Decisive.
Here, 'beslissende' is used as an adjective modifying 'rol', describing it as pivotal or determining.
Hij speelde een beslissende rol in de overwinning.
He played a decisive role in the victory.
In this sentence, 'beslissend' again acts as an adjective but refers to the critical nature of the 'moment'.
Het moment was beslissend voor de uitkomst van de wedstrijd.
The moment was decisive for the outcome of the game.
'Beslissende' here describes the 'keuze', indicating it was a choice with final implications.