'Watch' in the Bible

Seeing them straining at the oars, for the wind was against them, at about the fourth watch of the night He *came to them, walking on the sea; and He intended to pass by them.

And He was giving orders to them, saying, “Watch out! Beware of the leaven of the Pharisees and the leaven of Herod.”

And He *said to them, “My soul is deeply grieved to the point of death; remain here and keep watch.”

And He *came and *found them sleeping, and *said to Peter, “Simon, are you asleep? Could you not keep watch for one hour?