omit vs omission

omit is not a noun while omission is a noun.

Word	Noun	Adjective	Verb	Adverb
omit	No	No	Yes	No
omission	Yes	No	No	No

omit (noun)	omission (noun)
	a mistake resulting from neglect
	neglecting to do something; leaving out or passing over something
	any process whereby sounds or words are left out of spoken words or phrases
	something that has been omitted

omit (verb)	omission (verb)
leave undone or leave out
prevent from being included or considered or accepted