exhalation vs expiration

exhalation and expiration both are nouns.

Word	Noun	Adjective	Verb	Adverb
exhalation	Yes	No	No	No
expiration	Yes	No	No	No

As nouns, exhalation and expiration are synonyms defined as:

Other synonyms of exhalation include breathing out.

exhalation (noun)	expiration (noun)
the act of expelling air from the lungs	the act of expelling air from the lungs
exhaled breath	euphemistic expressions for death
	a coming to an end of a contract period