foreplay vs kissing

foreplay and kissing both are nouns.

Word	Noun	Adjective	Verb	Adverb
foreplay	Yes	No	No	No
kissing	Yes	No	No	No

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

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

Other hyponyms of foreplay include caressing, cuddling, fondling, hugging, necking, petting, smooching, snuggling, feel.

foreplay (noun)	kissing (noun)
mutual sexual fondling prior to sexual intercourse	affectionate play (or foreplay without contact with the genital organs)