slap vs smack

slap and smack both are nouns.

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

As nouns, slap and smack are synonyms defined as:

slap and smack: the act of smacking something; a blow delivered with an open hand

Other synonyms of slap include smacking.

As nouns, slap and smack are synonyms defined as:

As adverbs, slap and smack are synonyms defined as:

Other synonyms of slap include bang, bolt, slapdash.

slap (noun)	smack (noun)
the act of smacking something; a blow delivered with an open hand	the act of smacking something; a blow delivered with an open hand
a blow from a flat object (as an open hand)	an enthusiastic kiss
	street names for heroin
	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)

slap (verb)	smack (verb)
hit with something flat, like a paddle or the open hand	press (the lips) together and open (the lips) noisily, as in eating
to play music at loud volume	kiss lightly
	deliver a hard blow to
	have a distinctive or characteristic taste
	have an element suggestive (of something)

slap (adverb)	smack (adverb)
directly	directly