'Guard' in the Bible

Be on guard so that you do not forget the covenant of the Lord your God that he has made with you, and that you do not make an image of any kind, just as he has forbidden you.

If you build a new house, you must construct a guard rail around your roof to avoid being culpable in the event someone should fall from it.

When you go out as an army against your enemies, guard yourselves against anything impure.