Source : Webster's Revised Unabridged Dictionary (1913)

Patrolman \Pa*trol"man\, n.; pl. {Patrolmen}.
   One who patrols; a watchman; especially, a policeman who
   patrols a particular precinct of a town or city.

Source : WordNet®

patrolman
     n : a policeman who patrols a given region [syn: {flatfoot}]