A phrase tacked on to the end of any bigoted, biased, hurtful, wrong or simply stupid remark. The speaker tacks on the phrase with the intent absolving themselves of any guilt or argument over the statement.
Danielle: Oh my god Becky, look at her butt! She's really asking for it in that skirt, just sayin.
Becky: Exactly WHAT are you “ just sayin”? That she deserves to get raped because she’s wearing a short skirt?