group action; collective behavior; collective behaviour; acting as a group
leading group (of runners in a marathon, etc.); leading pack
living in a group; communal living; community life
group suicide; mass suicide; arranged suicide of two or more people
going to school in groups
mass infection; infection outbreak; infection cluster
group suicide; mass suicide
gang assault; mob violence; gang rape
class action; class-action suit; class-action lawsuit
mass outbreak (of a disease)
employment en masse (esp. of middle and high school graduates from the rural districts during Japan's post-war economic boom)
gang stalker; mass stalker; gang stalking; mass stalking
group medical examination
groupism; group mentality; collectivism
organized crime syndicate; criminal group; (lit.) antisocial group
consanguineous group; kin group
social group with common ties to a region
collectivization of agriculture (in the Soviet Union)
occupational group; professional group; occupational cohort
crime whose goal requires a large number of people acting together (e.g. insurrection)
criminal organization; organized crime group
ultra-leftist violent group; far-left extremist group
Air Developing and Proving Command