cuddling vs petting

cuddling and petting both are nouns.

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

As nouns, cuddling and petting are synonyms defined as:

cuddling and petting: affectionate play (or foreplay without contact with the genital organs)

Other synonyms of cuddling include caressing, fondling, hugging, kissing, necking, smooching, snuggling.

cuddling (noun)	petting (noun)
affectionate play (or foreplay without contact with the genital organs)	affectionate play (or foreplay without contact with the genital organs)