Source : Webster's Revised Unabridged Dictionary (1913)

Patrol \Pa*trol"\, v. i. [imp. & p. p. {Patrolled}; p. pr. & vb.
   n. {Patrolling}.] [F. patrouiller, O. & Prov. F. patrouiller
   to paddle, paw about, patrol, fr. patte a paw; cf. D. poot
   paw, G. pfote, and E. pat, v.]
   To go the rounds along a chain of sentinels; to traverse a
   police district or beat.

Source : WordNet®

patrol
     n 1: a detachment used for security or reconnaissance
     2: the activity of going around or through an area at regular
        intervals for security purposes
     3: a group that goes through a region at regular intervals for
        the purpose of security
     [also: {patrolling}, {patrolled}]

patrol
     v : maintain the security of by carrying out a control [syn: {police}]
     [also: {patrolling}, {patrolled}]

patrolled
     See {patrol}