mastEnglishOxford English Thesaurusmast noun 1 a ship's mast: spar, boom, yard, gaff, foremast, mainmast, topmast, mizzenmast, mizzen, royal mast; archaic stick. 2 the mast on top of the building: flagpole, flagstaff, pole, post, rod, support, upright; aerial, transmitter, pylon.mast (1) Oxford Dictionary of English