This is the 4567th most frequent Dutch word.
derna
"Derna" is not a standard Dutch word. You may mean "daarna," which means "after that" or "then."
In this sentence, 'derna' is used to mean 'afterwards', referring to a moment following a previous action.
Na het eten gingen we wandelen en derna speelden we een spel.
After dinner, we went for a walk and afterward we played a game.
'Derna' here introduces a subsequent event, describing a sequence of occurrences.
Eerst viel de stroom uit, en derna hoorde we een harde knal.
First, the power went out, and then we heard a loud bang.
Here, 'derna' indicates the event occurring immediately after the prior action, signifying a direct temporal progression.