watch and ward

Definitions

1. The charge or care of certain officers to keep a watch by night and a guard by day in towns, cities, and other districts, for the preservation of the public peace.
   historical, uncountable
2. Uninterrupted vigilance.
   broadly, uncountable

Examples

“The narrow seas around these isles, where British admirals keep⟳ watch⟳ and ward upon the marches of the Atlantic Ocean, are subject to the turbulent sway of the West Wind.”

“1917, Lee Wilson Dodd, "To America" (poem), in Fifes and Drums You need⟳ A starker breed⟳ To cherish you and guard, Keep⟳ watch⟳ and ward, Or strike⟳ if strike⟳ they must!”

CEFR level