A term used to describe someone who is acting dumber than they are; not necessary derogative term, but when used in the right context it can convey the frustration that one is having during the communication process.
Stop being such a schmuck and listen to me ya dumb!
A white man that steps in to take over the father role of a child after the black father has left the mother and child forever. In order for the man to be a Schmuck, the mother must also be white, leaving the couple to raise a child that obviously does not belong to the father biologically.
Poor John, no matter how great of a guy he is, everyone can plainly see that little Jamal isn't his. I guess his wife liked dark meat before she met him. John gets no respect.........what a Schmuck.