Literally translated destained fashion. Other translations: bad fashion (dress or behavior), bad taste. Used when you dont like were the person is going with their thoughts, and/or how the person is dressed.
Person A: They say there is a ghost that lives on this house.
Person B: Pish posh, your just trying to scare me.
Person A: Damn, you have a pish posh of clothes.
Person B: Your clothes are all sorts of pish posh.