мент

Policeman, the fuzz — quite often used, if police officers are out of earshot. Loaned from Polish, where mente has been used as slang for soldiers or guards (initially it is a Hungarian word for a short coat-cape, also called “fur attila” that was part of policemen’s uniform).

У ментов маленькая зарплата, но хорошие доходы.

Coppers have small salaries but comfortable income.

Ментам писькой по губам (“Hit cops with dicks on the lips”),
Graffiti in Moscow, podkolokolnyj per. (June 2008)

An angel passed, literally “a cop was born” (said when sudden silence appears). When a sudden, unexpected, and complete silence falls over a group of people having an active conversation, this phrase is jokingly and cynically blurted out to break the tension.

— Мент родился, — прокомментировал Никита тишину, но она вдруг снова нарушилась: на сей раз посторонним шумом с улицы.

— A cop is born, — Nikita commented on the silence, but it was suddenly interrupted again: this time by an outside noise from the street.

(Евгений Козловский, Гувернантка)

Police station, cop shop. Referring to the physical building of a police station or being detained there.

Вдруг её остановят, проверят документы, препроводят в ментовку и запрут вместе с проститутками.

Suddenly she is stopped, ID check, she is transferred to the nick and locked up with the prostitutes.

(Виктория Токарева, Своя правда, 2002)