"patrols" in the noun sense
a detachment used for security or reconnaissance
the activity of going around or through an area at regular intervals for security purposes
a group that goes through a region at regular intervals for the purpose of security
"patrols" in the verb sense
1. patrol, police
maintain the security of by carrying out a patrol
Source: WordNet® (An amazing lexical database of English)
Princeton University "About WordNet®."
WordNet®. Princeton University. 2010.
View WordNet® License