posse

1. (now historical, in later use chiefly US) A group of people summoned to help law enforcement.Examples: "He […] no sooner set his nose within the room to which he was directed, than the constable and his posse sprung upon him, before he had the least intimation of his design, or any opportunity of acting in his own defence."; "Mathews then appointed Morton as a deputy sheriff and after a posse had been selected, they went in pursuit of the criminals. Within a few hours, the posse overtook the thieves."; "While Wyatt dismounted and aimed his shotgun at Brocius, the rest of his posse retreated."historical

2. (US) A search party.US

3. (US, Jamaica, slang) A criminal gang.Examples: "Jamaican posses can be traced back to the Jamaican neighborhoods, and posse names correspond to the names of each neighborhood in which the gangs operate."JamaicaUSslang

4. (colloquial) A group of (especially young) people seen as constituting a peer group or band of associates; a gang, a group of friends.Examples: "Hey, sir? Sir, excuse me?” The blonde was calling out to him, in imperious tones that insisted on a reply. […] She was breaking a rule of big-city life, breaking it brazenly, sure of her power, confident of her turf and posse, fearing nothing."; "But the few friends that I DO have are my “ride or die” chicks—my posse."colloquial