This is the 7710th most frequent Polish word.
mzk
"MZK" stands for "Miejski Zakład Komunikacji," meaning "Municipal Transport Company" in English.
Here, 'MZK' refers to the public transportation system that the person uses for commuting.
Korzystam z MZK, aby dojechać do szkoły.
I use the MZK to get to school.
In this case, 'MZK' is mentioned in the context of purchasing a ticket for access to the service.
Czy kupiłeś bilet na MZK?
Did you buy a ticket for MZK?
Here, 'MZK' represents the organization responsible for city public transport, involved in planning and introducing new routes.