The Nuttall Encyclopedia
A tunic without sleeves worn by military nobles over their arms, generally emblazoned with heraldic devices. "Toom Tabard," empty king's cloak, nickname given by the Scotch to John Balliol as nothing more.
Wood, James, ed. Entry for 'Tabard'. The Nuttall Encyclopedia. https://www.studylight.org/encyclopedias/eng/nut/t/tabard.html. Frederick Warne & Co Ltd. London. 1900.