Beating is striking more than once, in violence, beating a drum, etc. This is the original meaning of the word.
Beating can mean to defeat someone in any sort of contest, or to get to something before someone else.
In physics and sound, a beat is the oscillation between zero intensity and full intensity that occurs when two frequencies (which are not harmonically related) are added together, caused by alternating constructive and destructive interference of the pressure waves. Beating is heard as a pulsation in loudness of two nearby frequencies, f1 and f2, at the rate of |f1 − f2|. Thus f = 0 when the two waves are in unison and as the difference between f1 and f2 increases, the speed increases until beyond a certain proximity beating becomes undetectable and a roughness is heard instead, after which the two pitches are perceived as separate. Beating can also be heard between notes that are near to, but not exactly, a harmonic interval. The composerAlvin Lucier has written many pieces which feature interference beats as their main focus. Musicians commonly use interference beats to objectively check tuning at the unison, perfect fifth, or other simple harmonic intervals. (See also heterodyne.)
In theater, a beat can refer to a short pause inserted into an actor's delivery; Harold Pinter is known for explicitly scripting these beats and pauses into his plays.
police: Beat is the territory and time that a police officer patrols.
In Sport and Fencing a beat is a type of attack known as a preparation where the attacker strikes the middle of their opponents blade with the middle of their blade and there by knocking it out of the way and then allowing them to strike their opponent.