What does unmarked mean?
unmarked
Definition
Of a police car: looking like an ordinary car, with no police markings or lights on show.
Example sentences
That gray sedan behind us is an unmarked police car — see the little lights in the grille?
That gray sedan behind us is an unmarked police car — see the little lights in the grille?
The detectives who came to take our statement parked an unmarked car outside, and the neighbors just assumed we had guests.