stimulation vs petting

stimulation and petting both are nouns.

Word	Noun	Adjective	Verb	Adverb
stimulation	Yes	No	No	No
petting	Yes	No	No	No

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

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

Other hyponyms of stimulation include caressing, cuddling, fondling, hugging, kissing, necking, smooching, snuggling, feel.

stimulation (noun)	petting (noun)
the act of arousing an organism to action	affectionate play (or foreplay without contact with the genital organs)
mutual sexual fondling prior to sexual intercourse
any stimulating information or event; acts to arouse action
(physiology) the effect of a stimulus (on nerves or organs etc.)