This is the 2949th most frequent Polish word.
niepodległości
"Niepodległości" means "independence."
Here, 'Niepodległości' is used as part of a proper noun to signify the name of the day celebrating national independence.
Dzień Niepodległości w Polsce jest obchodzony 11 listopada.
Independence Day in Poland is celebrated on November 11.
In this sentence, 'niepodległości' is used as an abstract concept representing the state of being independent.
Mieszkańcy kraju dumnie świętowali kolejny rok niepodległości.
The citizens of the country proudly celebrated another year of independence.
In this case, 'niepodległości' denotes the goal or state of regaining independence.