This is the 5252nd most frequent Polish word.
rocznica
"Rocznica" means "anniversary."
Use of the word 'rocznica' to denote a specific annual commemoration, here referring to a marriage anniversary.
Nasza rocznica ślubu przypada na przyszły tydzień.
Our wedding anniversary is next week.
Use of 'rocznica' to signify a yearly occasion marking an event, in this case, the opening of a store.
Dzisiaj mamy rocznicę otwarcia sklepu.
Today we have the anniversary of the store's opening.
Use of the term 'rocznica' to depict national or historical anniversaries, which are commemorated events.