breathing in vs breathing

breathing in and breathing both are nouns.

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

breathing in (noun)	breathing (noun)
the act of inhaling; the drawing in of air (or other gases) as in breathing	the bodily process of inhalation and exhalation; the process of taking in oxygen from inhaled air and releasing carbon dioxide by exhalation

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