This is the 809th most frequent Norwegian word.
rekorden
"The record."
The word 'rekorden' is used in the definite singular form to indicate a specific, known record (fastest time in a marathon).
Han slo rekorden for raskest tid på maraton.
He broke the record for the fastest time in the marathon.
The word 'rekorden' refers specifically to the speaker's own prior best achievement in swimming.
Jeg prøver å forbedre rekorden min i svømming.
I am trying to improve my record in swimming.
Here, 'rekorden' pertains to a specific achievement or milestone set by the team.