standstill vs impasse

standstill and impasse both are nouns.

Word	Noun	Adjective	Verb	Adverb
standstill	Yes	No	No	No
impasse	Yes	No	No	No

As nouns, standstill and impasse are synonyms defined as:

standstill and impasse: a situation in which no progress can be made or no advancement is possible

Other synonyms of standstill include dead end, deadlock, stalemate.

standstill (noun)	impasse (noun)
an interruption of normal activity	a street with only one way in or out
a situation in which no progress can be made or no advancement is possible	a situation in which no progress can be made or no advancement is possible