sentinel
US /ˈsen.t̬ɪ.nəl/
UK /ˈsen.tɪ.nəl/
名詞
歩哨
a soldier or guard whose job is to stand and keep watch.
動詞
歩哨
station a soldier or guard by (a place) to keep watch.
例:
•
a wide course had been roped off and sentineled with police