the GNU version of the Collaborative International Dictionary of English
n. The act or process of putting a mast or masts into a vessel; also, the scientific principles which determine the position of masts, and the mechanical methods of placing them.
The Century Dictionary and Cyclopedia
n. On a sailing-vessel, the arrangement of the masts and their supports.
Word Usage
"Members of the Privy Council are honoured by half-masting of the flag on the Peace Tower of the Parliament Buildings in Ottawa when they die."