mercer UK /ˈmɜːsə/US /ˈmɝsɚ/ noun1 •A merchant dealing in fabrics and textiles, especially silks and other fine cloths.... Acolastus-Polypragmon-Asotus, is here present (by the help of his mercer, tailor, milliner, sempster, and so forth) at his designed hour... — 1600 formsmercers