tonjon UK /ˈtɒndʒɒn/US /ˈtɑnˌdʒɑn/ noun1 •(historical) An open sedan chair raised on single poles front and back.The old tonjons were still to be seen in the basement at Barrackpore some years before my time, but when I enquired for them, they had disappeared. — 1925 formstonjons