Beat - Glasgledius

physics: Beat is the perception of the sum of two close frequencies as one frequency that oscillates between zero intensity and full intensity, caused by the alternating constructive and destructive interference.
music theory: Beat is any of the periodic transient signals in music that mark the rhythm. DJs often beatmatch the songs that they play.
literature: Beat is a genre of literature written by beatniks. See: Beat Generation.
police: Beat is the territory and time that a police officer patrols.
musical genre: Beat style played in the 1960s