This is the 336th most frequent Polish word.
francji
"Francji" means "of France" or "France" in the locative/genitive case in Polish.
The word 'Francji' is the locative case form of 'Francja', used here to indicate the location of the action.
Spędziłem wakacje we Francji.
I spent my vacation in France.
'Francji' is in the genitive case, indicating origin or association in this sentence.
Smak sera z Francji jest wyjątkowy.
The taste of cheese from France is exceptional.
'Francji' is also in the locative case here, employed after the preposition 'o' to refer to the topic of discussion.