camp-follower
n
1 non-military person (eg a prostitute) following an army to sell goods or services 随军售货或服务的非军事人员（如营妓）.
2 (often derog 常作贬义) person who attaches himself to a particular group, party, etc although not a member of it; hanger-on 依附於某一团体而并非其成员者; 跟随者.