Disown, v. t. [imp. & p. p. Disowned; p. pr. & vb. n. Disowning.]
1. To refuse to own or acknowledge as belonging to one's self; to disavow or deny, as connected with one's self personally; as, a parent can hardly disown his child; an author will sometimes disown his writings.
2. To refuse to acknowledge or allow; to deny. Then they, who brother's better claim disown, Expel their parents, and usurp the throne. Dryden.
Syn. -- To disavow; disclaim; deny; abnegate; renounce; disallow.
Shades of meaning
Fernald has no entry of its own for disown; he lists it under renounce.
Where he writes about it:
A person may deny, disavow, disclaim, disown what has been truly or falsely imputed to him or supposed to be his. — from renounce
He may deny his signature, disavow the act of his agent, disown his child; he may repudiate a just claim or a base suggestion. — from renounce