This is the 8699th most frequent French word.
autopatrouille
Police car.
Here, 'autopatrouille' is used as a noun to describe a police vehicle patrolling an area.
L'autopatrouille surveille le périmètre ce soir.
The patrol car is monitoring the perimeter tonight.
In this sentence, 'autopatrouille' is referred to audibly to indicate the familiarity of its sound.
Le bruit de l'autopatrouille est reconnaissable de loin.
The sound of the patrol car is recognizable from afar.
Here, the term 'autopatrouille' depicts the visual occurrence of police vehicles seen in motion.