disown vs reject

disown is not a noun while reject is a noun.

Word	Noun	Adjective	Verb	Adverb
disown	No	No	Yes	No
reject	Yes	No	Yes	No

As verbs, reject is a hypernym of disown; that is, reject is a word with a broader meaning than disown:

disown (noun)	reject (noun)
	the person or thing that is rejected or set aside as inferior in quality

disown (verb)	reject (verb)
cast off	not accept something given or offered
prevent deliberately (as by making a will) from inheriting	dismiss from consideration or a contest
	deem wrong or inappropriate
	reject with contempt
	not accept as true
	refuse entrance or membership
	resist immunologically the introduction of some foreign tissue or organ