noun
unlicensed taxi; illegal cab
Colloquial term for a private car used as an illegal taxi, often distinguished from licensed taxis by its white license plate.
駅前に白タクが客待ちをしている。
An unlicensed taxi is waiting for passengers in front of the station.
白タク行為は法律で禁止されている。
Operating an unlicensed taxi is prohibited by law.