deadbeat dad

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun idiomatic, derogatory A man, especially one who is divorced or estranged from his partner, who fails to provide monetary child support when he is legally required to do so.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a father who willfully defaults on his obligation to provide financial support for his offspring