This is the 75th most frequent Polish word.
czasu
The word "czasu" in Polish means "time" (genitive case).
The word 'czasu' here is used in the genitive case to denote the quantity of time the speaker possesses.
Mam dużo wolnego czasu w weekendy.
I have a lot of free time on weekends.
In this example, 'czasu' is also in the genitive case, expressing the lack or limited quantity of time.
Nie miałem za dużo czasu, aby cię odwiedzić.
I didn't have much time to visit you.
Here, 'czasu' shows a completed aspect or the lack of time, again using the genitive case.