patrol

1. (military) A going of the rounds along the chain of sentinels and between the posts, by a guard, usually consisting of three or four men, to insure greater security from attacks on the outposts.Examples: "Four members of the squadron were on patrol."; "The watch consisted of twelve convicts—men selected for their good behaviour. Immediately after tattoo had beat they began their patrol. 'No complaint was ever made of them,' remarks Phillip, and they were expressly cautioned to avoid disputes with soldiers or seamen ( many of whom were as great thieves as the convicts themselves)."countableuncountable

2. (military) A movement, by a small body of troops beyond the line of outposts, to explore the country and gain intelligence of the enemy's whereabouts.countableuncountable

3. (military) The guards who go the rounds for observation; a detachment whose duty it is to patrol.Examples: "After cordial good-bye to our hospitable hostess we motored back to Chaumont where we dined with Colonel Mitchell; and then with another long drive we finally reached home tired but happy at 3.30 in the morning. There staring me in the face was an order directing me to lead my patrol over the lines in the morning at five o'clock, sharp! An hour and a half sleep for an utterly worn out aviator!"countableuncountable

4. (law enforcement) The largest division of officers within a police department or sheriff's office, whose assignment is to patrol and respond to calls for service.countableuncountable

5. (scouting) A unit of a troop, usually defined by certain ranks or age groups within the troop, and ideally comprised of six to eight members.Examples: "On a makeshift bed in the corner was an old woman looking very sick. Then a patrol of "Missioner" Scouts appeared on the scene: one seized a broom and swept out the room; the next made up the fire with some fuel he had procured and made her a cup of tea; another mended the rickety table, bed and chair, making them at any rate serviceable, while a fourth straightened out the bedclothes, propped the old lady up, and did his best to cheer her until the tea was ready."; "The formation of the boys into Patrols of from six to eight and training them as separate units each under its own responsible leader is the key to a good Troop."countableuncountable