sentinel
noun [ C ] uk/ˈsen.tɪ.nəl/ us/ˈsen.t̬ɪ.nəl/
literary岗哨；哨兵
a person employed to guard something
A policeman stood sentinel at the entrance. 一个警察站在入口处放哨。
Synonym: sentry
mainly US（用于某些报纸名中）
Sentinel is also used in the names of some newspapers.
the Fort Lauderdale Sun-Sentinel 《劳德代尔堡太阳卫报》