snogging vs snuggling

snogging and snuggling both are nouns.

Word	Noun	Adjective	Verb	Adverb
snogging	Yes	No	No	No
snuggling	Yes	No	No	No

As nouns, snuggling is a hypernym of snogging; that is, snuggling is a word with a broader meaning than snogging:

snogging: (British informal) cuddle and kiss
snuggling: affectionate play (or foreplay without contact with the genital organs)

Other hypernyms of snogging include caressing, cuddling, fondling, hugging, kissing, necking, petting, smooching.

snogging (noun)	snuggling (noun)
(British informal) cuddle and kiss	affectionate play (or foreplay without contact with the genital organs)