impasse vs deadlock

impasse and deadlock both are nouns.

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

As nouns, impasse and deadlock are synonyms defined as:

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

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

impasse (noun)	deadlock (noun)
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