This is the 4377th most frequent Polish word.
herbaty
"Herbaty" means "tea" (genitive singular or nominative plural).
In this sentence, 'herbaty' is in the genitive case, indicating what is requested (a cup of tea).
Poproszę filiżankę herbaty.
I would like a cup of tea.
Here, 'herbaty' is used in the genitive case to denote lack or absence of tea.
Nie mamy już herbaty.
We don't have any tea left.
Here, 'herbaty' appears in the genitive case as part of a descriptive phrase about the ingredient added to the cake.