bio-dad 

biological father, as opposed to the person your mother married after divorce

So we’re having this party at my bio-dad’s summer house and we’d love if you could join us?

bio-dad by mk fresh November 8, 2007

bio-dad 

your biological father as opposed to your stepfather.

So we’re having this party at my bio-dad’s summer house and we’d love if you could join us?

bio-dad by cheesemac November 1, 2007

bio-dad 

The guy that knocked you up and either bailed or you kicked him to the curb. Not involved in the child's life except maybe enforced support payments. If you're a dude, what the baby mama calls you.

Tiffany met her bio-dad for the first time last week. Her first reaction was "What was Mom thinking?"

bio-dad by sendmorecoffee August 1, 2008

bio-dad 

The S.O.B. who fathered you but didn't take the time or care to ever meet you.

I never met my bio-dad, that sob, Charles Carroll Palmisano.

bio-dad by Safffernellie December 5, 2009

bio dad

What a casual relationship might end up as for the guy. The male part of the fertilization process. See sperm donor

That bio dad has 4 other kids by 4 other chicks.

bio dad by Filamena C June 18, 2008