Meaning

• A group of twelve items.

  "Fractions would be a little easier if we counted by twelves."

• A twelve-bore gun.

• A jury (normally composed of twelve persons).

• Police; law enforcement, especially a narcotics officer

Meaning

• The cardinal number occurring after eleven and before thirteen, represented in Arabic numerals as 12 and in Roman numerals as XII.

  "There are twelve months in a year."

• Law enforcement; the police