impasse vs dead end

impasse and dead end both are nouns.

Word	Noun	Adjective	Verb	Adverb
impasse	Yes	No	No	No
dead end	Yes	No	No	No

As nouns, impasse and dead end are synonyms defined as:

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

Other synonyms of impasse include deadlock, stalemate, standstill.

impasse (noun)	dead end (noun)
a street with only one way in or out	a passage with access only at one end
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