a deckhouse built around a mast as a platform for cargo-handling machinery, gear, and controls.
(formerly) a towerlike crane for stepping and removing masts from ships or boats.
a building in which masts are made.
Origin of mast house
First recorded in 1760–70
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for mast house
Historical Examples of mast house
Before leaving we went into the mast-house, near the entrance to the yard.A Yacht Voyage Round England