kiss vs smack

kiss and smack both are nouns.

Word	Noun	Adjective	Verb	Adverb
kiss	Yes	No	Yes	No
smack	Yes	No	Yes	Yes

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

Other hyponyms of kiss include smooch, deep kiss, French kiss, soul kiss, peck.

As verbs, smack is a hyponym of kiss; that is, smack is a word with a more specific, narrower meaning than kiss:

kiss: touch with the lips or press the lips (against someone's mouth or other body part) as an expression of love, greeting, etc.
smack: kiss lightly

Other hyponyms of kiss include peck.

kiss (noun)	smack (noun)
the act of caressing with the lips (or an instance thereof)	the act of smacking something; a blow delivered with an open hand
a light glancing touch	an enthusiastic kiss
any of several bite-sized candies	street names for heroin
a cookie made of egg whites and sugar	a sailing ship (usually rigged like a sloop or cutter) used in fishing and sailing along the coast
	the taste experience when a savoury condiment is taken into the mouth
	a blow from a flat object (as an open hand)

kiss (verb)	smack (verb)
touch with the lips or press the lips (against someone's mouth or other body part) as an expression of love, greeting, etc.	press (the lips) together and open (the lips) noisily, as in eating
touch lightly or gently	kiss lightly
	deliver a hard blow to
	have a distinctive or characteristic taste
	have an element suggestive (of something)

kiss (adverb)	smack (adverb)
	directly