1. (v. i.) To go the rounds along a chain of sentinels; to traverse a police district or beat.

2. (v.) t To go the rounds of, as a sentry, guard, or policeman; as, to patrol a frontier; to patrol a beat.

3. (n.) 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.

4. (n.) 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.

5. (n.) The guard or men who go the rounds for observation; a detachment whose duty it is to patrol.

6. (v. i.) Any perambulation of a particular line or district to guard it; also, the men thus guarding; as, a customs patrol; a fire patrol.

Argus Charley airplane spotter beat course cover defend defending do fire patrolman fire warden fireguard forward observer go over guard guarding keep guard keep vigil keep watch lookout lookout man measure mount guard night watchman overpass pass over pass through patroller patrolman perambulate peregrinate pererrate picket ply police protect protecting protection range range over reconnoiter rounds roundsman safeguarding scour scour the country scout sentinel sentry spotter stand guard stand sentinel sweep track transit travel over travel through traverse vedette vigilance voyage watch watch over watcher watchfulness watchkeeper watchman