Wiktionary
vb. (context idiomatic intransitive English) To guard; to watch over someone or something.
Usage examples of "keep watch".
Even so, Hans had left his operations officer in charge below, seated in the command chair to view the screen and keep watch over the rest of the area via his virtual reality helmet.
They were posted here not only to keep watch over Earth, but over the activities of their rivals, the Dirnans, as well.
From this vantage point they could watch the entire length of the entry corridor to their left, all the way to the black square of night that was the courtyard, and at the same time keep watch on the prison block to their right.
I was not inclined to risk much for man or woman in Bulika, but the life of a child might well be worth such a poor one as mine, and I resolved to keep watch at that door the rest of the night.
I laid myself a little way from her, with the body of Lona by my other side, thus to keep watch at once over the dead and the dangerous.
Go to the stream there, under the trees, keep watch and wait until I return.
And I'll wait with Pashenka meantime and will keep watch on him through Nastasya.
The best surveillance they had indicated that the ridge top would be empty, but they took half an hour making sure that it was, before Skinner took up a post where he could keep watch, and Washington motioned for the others to come up.
He's found three, and he says be will keep watch beside the roads, and through the woods while he hunts.
The King therefore sent his spies to keep watch over the foe, to see what he was doing and to send word of his every movement.
Thereupon the Raj a sent off one of the Raj puts and Lal Das with an order for the rest of the retainers to keep watch in case the tiger returned unexpectedly.
The deck was deserted, for it was unnecessary to keep watch in that tranquil harbor.
So, all round the isle, the toddy-cutters sit on high, and are rocked by the trade, and have a view far to seaward, where they keep watch for sails, and like huge birds utter their songs in the morning.
With Naginlta she would scout the quarry and keep watch, leaving the men to take the longer way around.
In the next engagement they would try to keep watch of him to discover when he would run.