noun the vertical post of a derrick or crane.
2. mast ·noun the fruit of the oak and beech, or other forest trees; nuts; acorns.
3. mast ·vt to furnish with a mast or masts; to put the masts of in position; as, to mast a ship.
4. mast ·add. ·noun a spar or strut to which tie wires or guys are attached for stiffening purposes.
5. mast ·noun a pole, or long, strong, round piece of timber, or spar, set upright in a boat or vessel, to sustain the sails, yards, rigging, ·etc. a mast may also consist of several pieces of timber united by iron bands, or of a hollow pillar of iron or steel.