Definition of "mast"
mast1
/mɑːst/
noun
plural masts
(nautical, communication, aviation) A tall, slim post or tower, usually tapering upward, used to support, for example, sails or observation platforms on a ship, the main rotor of a helicopter, flags, floodlights, meteorological instruments, or communications equipment, such as an aerial, usually supported by guy-wires (except in the case of a helicopter).
mast2
/mɑːst/
verb
third-person singular simple present masts, present participle masting, simple past and past participle masted
mast3
/mɑːst/
noun
uncountable