horniness vs sexual arousal

horniness and sexual arousal both are nouns.

Word	Noun	Adjective	Verb	Adverb
horniness	Yes	No	No	No
sexual arousal	Yes	No	No	No

As nouns, sexual arousal is a hypernym of horniness; that is, sexual arousal is a word with a broader meaning than horniness:

horniness: a state of sexual arousal
sexual arousal: the arousal of sexual desires in preparation for sexual behavior

horniness (noun)	sexual arousal (noun)
a state of sexual arousal	the arousal of sexual desires in preparation for sexual behavior