arousal vs caressing

arousal and caressing both are nouns.

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

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

arousal: mutual sexual fondling prior to sexual intercourse
caressing: affectionate play (or foreplay without contact with the genital organs)

Other hyponyms of arousal include cuddling, fondling, hugging, kissing, necking, petting, smooching, snuggling, feel.

arousal (noun)	caressing (noun)
the act of arousing	affectionate play (or foreplay without contact with the genital organs)
mutual sexual fondling prior to sexual intercourse
awakening from sleep
a state of heightened physiological activity