plead·er \ˈplēdə(r)\noun (-s) Etymology: Middle English pleder, alteration of plaidur, plaitour, pletour, from Old French plaideor, from plaidier to plead + -eor -or — more at plead 1. a.: one who conducts legal pleas especially in court : advocate b.: one who files a legal pleading 2.: one who pleads : intercessor