breathing vs expiration

breathing and expiration both are nouns.

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

breathing (noun)	expiration (noun)
the bodily process of inhalation and exhalation; the process of taking in oxygen from inhaled air and releasing carbon dioxide by exhalation	the act of expelling air from the lungs
	euphemistic expressions for death
	a coming to an end of a contract period

breathing (adjective)	expiration (adjective)
passing or able to pass air in and out of the lungs normally; sometimes used in combination