rhythm vs beat

rhythm and beat both are nouns.

Word	Noun	Adjective	Verb	Adverb
rhythm	Yes	No	No	No
beat	Yes	Yes	Yes	No

As nouns, rhythm and beat are synonyms defined as:

Other synonyms of rhythm include musical rhythm.

rhythm (noun)	beat (noun)
natural family planning in which ovulation is assumed to occur 14 days before the onset of a period (the fertile period would be assumed to extend from day 10 through day 18 of her cycle)	the act of beating to windward; sailing as close as possible to the direction from which the wind is blowing
recurring at regular intervals	a stroke or blow
(architecture) the repetitive use of a group of visual elements to establish a recognizable pattern	a regular rate of repetition
the arrangement of spoken words alternating stressed and unstressed elements	the basic rhythmic unit in a piece of music
the basic rhythmic unit in a piece of music	(prosody) the accent in a metrical foot of verse
an interval during which a recurring sequence of events occurs	the rhythmic contraction and expansion of the arteries with each beat of the heart
	the sound of stroke or blow
	a regular route for a sentry or policeman
	a member of the beat generation; a nonconformist in dress and behavior
	a single pulsation of an oscillation produced by adding two waves of different frequencies; has a frequency equal to the difference between the two oscillations

rhythm (adjective)	beat (adjective)
	very tired

rhythm (verb)	beat (verb)
	wear out completely
	be a mystery or bewildering to
	come out better in a competition, race, or conflict
	beat through cleverness and wit
	hit repeatedly
	give a beating to; subject to a beating, either as a punishment or as an act of aggression
	stir vigorously
	strike (a part of one's own body) repeatedly, as in great emotion or in accompaniment to music
	strike (water or bushes) repeatedly to rouse animals for hunting
	shape by beating
	make by pounding or trampling
	produce a rhythm by striking repeatedly
	move rhythmically
	sail with much tacking or with difficulty
	move with a flapping motion
	indicate by beating, as with the fingers or drumsticks
	move with a thrashing motion
	move with or as if with a regular alternating motion
	make a rhythmic sound
	make a sound like a clock or a timer
	glare or strike with great intensity
	avoid paying
	be superior