vice-n; 3 Senses

Sense Number 1: human weakness, generally

Commentary: Refers to the general evil in the world, not a specific kind. A mass noun.

Las Vegas is a wretched hive of vice and villainy.
He's a man weighed down with vice and greed.

WordNet 2.0 Sense Numbers: 1

Sense Number 2: a specific or personal weakness

Commentary: A type of human weakness, or one person's. Can have indeterminatives. A count noun.

Gambling has always been my vice.
He's a man of many vices, but womanizing worst among them.

WordNet 2.0 Sense Numbers: 2

Sense Number 3: police subgroup

Commentary: The part of a police force dedicated to regulating a specific type of crime, such as prostitution. Usually capitalized. The television show 'Miami Vice' referred to this sense.

John worked on Vice for thirty years.
We sent our Vice Squad to investigate.

WordNet 2.0 Sense Numbers: -