wallop vs impact

wallop and impact both are nouns.

Word	Noun	Adjective	Verb	Adverb
wallop	Yes	No	Yes	No
impact	Yes	No	Yes	No

As nouns, wallop and impact are synonyms defined as:

wallop (noun)	impact (noun)
a severe blow	influencing strongly
a forceful consequence; a strong effect	the violent interaction of individuals or groups entering into combat
	the striking of one body against another
	a forceful consequence; a strong effect

wallop (verb)	impact (verb)
defeat soundly and utterly	have an effect upon
strike hard	press or wedge together; pack together