A posse of people is a group of people with the same job or purpose.
例句
...a posse of reporters...一群记者A posse of Marsh's friends persuaded them that this was a bad idea.马什的一群朋友劝他们说这是个馊主意。
N-COUNT
（旧时美国县治安官调集协助其追捕罪犯的）民防团
In former times, in the United States, a posse was a group of men who were brought together by the local law officer to help him chase and capture a criminal.