Although the doctors had been able to 'keep her illness at bay' [=to prevent her illness from becoming worse] for a few months, the disease soon began to spread again.
Armed with a gun, he 'held the police at bay' [=he did not allow the police to arrest him] for 10 hours.
The soldiers 'kept the attackers at bay'. [=they did not allow the attackers to come closer]
(..) (YELLS) (YELLS) To the great hall! Astrid! We're in the wrong place! Torvi! Keep them at bay. - Hurry! - Yes! (BOTH GRUNTING) (SCREAMS) (GRUNTING) (..)2017 TvShow: Vikings Title: On the Eve Season: 4 Episode 19