This is the 520th most frequent French word.
arrêté
A legal or official decree, order, or regulation.
In this sentence, "arrêté" is used as a verb in past tense (past participle) meaning "arrested."
Le policier a arrêté le voleur.
The policeman arrested the thief.
Here, "arrêté" is used as a noun meaning "decree" or "official order."
Il a suivi le panneau qui disait "Arrêté municipal."
He followed the sign that said "Municipal decree."
In this case, "arrêté" is used as a past participle of the verb "arrêter" to convey the state of being stopped.