patrol

v. scout, make a reconnaissance tour; keep safe, maintain security

n. guard, watch; reconnaissance tour, scouting tour; squad car

For other meanings, see patrol (disambiguation). In military tactics, a patrol is a small tactical grouping sent out by land, sea or air to perform a specific task. A patrol may be a reconnaissance patrol, sent to investigate some feature of interest, or a fighting patrol (US combat patrol), sent to find and engage the enemy.
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Noun
1. a detachment used for security or reconnaissance
(hypernym) detachment
(derivation) police
2. the activity of going around or through an area at regular intervals for security purposes
(hypernym) protection
(hyponym) airborne patrol
(derivation) police
3. a group that goes through a region at regular intervals for the purpose of security
(hypernym) force, personnel
(hyponym) border patrol
(member-meronym) patroller
(derivation) police
Verb
1. maintain the security of by carrying out a control
(synonym) police
(hypernym) guard

n. patrol, guard, watch; reconnaissance tour, scouting tour; squad car

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

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

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

(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.
  

(v. i.)
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.
  

(v. i.)
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.