emergency vs crisis

emergency and crisis both are nouns.

Word	Noun	Adjective	Verb	Adverb
emergency	Yes	No	No	No
crisis	Yes	No	No	No

As nouns, crisis is a hypernym of emergency; that is, crisis is a word with a broader meaning than emergency:

emergency: a sudden unforeseen crisis (usually involving danger) that requires immediate action
crisis: a crucial stage or turning point in the course of something

emergency (noun)	crisis (noun)
a brake operated by hand; usually operates by mechanical linkage	a crucial stage or turning point in the course of something
a sudden unforeseen crisis (usually involving danger) that requires immediate action	an unstable situation of extreme danger or difficulty
a state in which martial law applies