arousal vs excitement

arousal and excitement both are nouns.

Word	Noun	Adjective	Verb	Adverb
arousal	Yes	No	No	No
excitement	Yes	No	No	No

As nouns, excitement is a hyponym of arousal; that is, excitement is a word with a more specific, narrower meaning than arousal:

arousal (noun)	excitement (noun)
the act of arousing	something that agitates and arouses
mutual sexual fondling prior to sexual intercourse	disturbance usually in protest
awakening from sleep	the feeling of lively and cheerful joy
a state of heightened physiological activity	the state of being emotionally aroused and worked up