1 N-COUNT 船桅;桅杆 The masts of a boat are the tall upright poles that support its sails. 船桅;桅杆

2 N-COUNT 天线杆 A radio mast is a tall upright structure that is used to transmit radio or television signals. 天线杆

3 to nail your colours to the mast→see: colour  to nail your colours to someone's mast→see: colour