This is the 2934th most frequent Polish word.
narodowe
"Narodowe" means "national" in English.
The word 'narodowe' is used here as an adjective modifying 'muzeum', indicating that the museum has a national significance or affiliation.
Narodowe muzeum jest miejscem pełnym historii.
The national museum is a place full of history.
'Narodowe' describes the holiday as one that pertains to the nation or is celebrated nationwide.
W święto narodowe, ludzie wywieszają flagi.
On the national holiday, people display flags.
In this context, 'narodowa' modifies 'gospodarka', emphasizing that the economy is related to or belongs to the nation.