a negative term used by both black and white people against a black person who hates the fact that they are black and wants to be white. many female oreos (happens with males too, just not as much) use skin-bleaching products for lightening the tone of their skin. most oreos also believe that they are better then other black people and think they all are beneath them.
commonly mistaken for an oreo is a black person who 'talks proper', or uses correct grammar, gets good grades, has white friends, listens to music genres other than rap and r&b, etc.
damn dat nigga deion is such a oreo. can't believe he's talkin shit bout his race while kissin up to da white folks.