This is the 8042nd most frequent Polish word.
niedzieli
"Niedzieli" means "Sunday" in English.
In this case, 'niedzieli' appears in the genitive case, showing anticipation towards the day.
Nie mogę doczekać się niedzieli.
I can't wait for Sunday.
Here, 'niedzieli' is used again in the genitive case, expressing the reason or cause for the store being closed.
Z powodu niedzieli sklep był zamknięty.
Because of Sunday, the store was closed.
Here, 'niedzieli' is used in the locative case, referring to 'Sunday' as a specific day when the event occurred.