'Watch' in the Bible

But Saul got knowledge of their design. And they kept watch day and night on the roads out of the town, so that they might put him to death:

And having taken him, he put him in prison, with four bands of armed men to keep watch over him; his purpose being to take him out to the people after the Passover.

And when Herod was about to take him out, the same night Peter was sleeping in chains between two armed men, and the watchmen were keeping watch before the door of the prison.

So keep watch, having in mind that for three years without resting I was teaching every one of you, day and night, with weeping.

And when we came into Rome, they let Paul have a house for himself and the armed man who kept watch over him.