guardian
/ˈgɑ:dɪən; `ɡɑrdɪən/ n
1 one who guards or protects sth 保护者; 保卫者; 维护者
The police are guardians of law and order. 警察是维护法纪的人.
a self-appointed guardian of public morality 自封的卫道士.
2 (law 律) person who is legally responsible for sb who cannot manage his own affairs, eg an orphaned child 保护人; 监护人.