This is the 12671st most frequent Polish word.
niedużo
"Not much" or "not many."
The word 'niedużo' functions here as an adverb quantifying the noun 'czas' (time).
Mam niedużo czasu, więc muszę się spieszyć.
I don't have much time, so I need to hurry.
The word 'niedużo' modifies the noun 'klientów' (customers), expressing a small quantity.
W sklepie było niedużo klientów.
There were not many customers in the store.
The word 'niedużo' here operates as an adverb modifying the verb 'mówiliśmy' (we spoke).