/'pɒsɪ; `pɑsɪ/
n [CGp] (esp US) group of people who can be summoned by an officer of the law, eg a sheriff, to find a criminal, maintain order, etc 地方武装团队（可由执法官员召集以查缉罪犯、维持治安等）.

n[C]
[Date: 1600-1700; Language: Medieval Latin;Origin: posse comitatus 'power of the county']
informal a group of the same kind of people
posse of
　I was surrounded by a posse of photographers.
a group of men gathered together by a sheriff (=local law officer) in the US in past times to help catch a criminal
AmE informala) someone's group of friends - used especially by young people
b) a group of friends from a particular place who share an interest in rap, hip-hop, or house music
British Equivalent: massive