farting vs breaking wind

farting and breaking wind both are nouns.

Word	Noun	Adjective	Verb	Adverb
farting	Yes	No	No	No
breaking wind	Yes	No	No	No

As nouns, farting and breaking wind are synonyms defined as:

farting and breaking wind: a reflex that expels intestinal gas through the anus

Other synonyms of farting include fart, flatus, wind.

farting (noun)	breaking wind (noun)
a reflex that expels intestinal gas through the anus	a reflex that expels intestinal gas through the anus