Meaning of “beat” - Learner’s Dictionary

beat

noun [ C ] uk us /biːt/
REGULAR SOUND

B2 a regular sound that is made by your heart or by something hitting a surface:

a heart beat
the beat of a drum
RHYTHM

B2 the main rhythm of a piece of music:

loud music with a repetitive beat
AREA

the area of a town or city that a police officer walks around regularly:

Having more police officers on the beat (= walking around their beat) should help to reduce crime.

(Definition of “beat noun” from the Cambridge Learner’s Dictionary © Cambridge University Press)