gang bang 
informal
noun
1The successive rape of one person by a group of people.
1.1A sexual orgy involving changes of partner.
2North American An instance of violence involving members of a criminal gang.
verb (gang-bang)
1 [with object] (Of a group of people) rape (someone).
2 (as noun gang-banging) North American The violent activities of a criminal gang.
Derivatives
gang-banger
- mounter
- mount guard
- Mountie
- Mountie hat
- Mountie's hat
- mounting
- mounting block
- mounting board
- mounting bracket
- mountingly
- mounting paper
- mounting point
- mounting ring
- Mount Isa
- Mountmellick
- Mount of Olives
- Mount of Piety
- Mount of Pity
- Mount Pleasant
- Mount Vernon
- mourn
- mourne
- Mourne Mountains
- mourner
- mourner's bench