impingement vs impaction

impingement and impaction both are nouns.

Word	Noun	Adjective	Verb	Adverb
impingement	Yes	No	No	No
impaction	Yes	No	No	No

As nouns, impingement and impaction are synonyms defined as:

impingement and impaction: a sharp collision produced by striking or dashing against something

impingement (noun)	impaction (noun)
influencing strongly	a sharp collision produced by striking or dashing against something
a sharp collision produced by striking or dashing against something	a disorder in which a tooth is so crowded in its socket that it cannot erupt normally
	a disorder in which feces are impacted in the lower colon
	the condition of being pressed closely together and firmly fixed