This is the 1454th most frequent Dutch word.
nadien
"Afterwards" or "subsequently."
Nadien is used here as an adverb meaning 'afterwards', referencing an event that occurred after a previously mentioned or understood action.
Nadien gingen we wandelen in het park.
Afterwards, we went for a walk in the park.
Nadien serves as a temporal connector, indicating the subsequent action of desserts being consumed after the meal.
Ze hadden veel gegeten, maar nadien was er nog plaats voor een dessert.
They had eaten a lot, but afterwards, there was still room for dessert.
Nadien ties the effort of studying to the resultant achievement of high grades, emphasizing the chronological sequence.