main-truck

Meaning

Noun

• On a wooden mast, a circular disc (or sometimes a rectangle) of wood near or at the top of the mast, usually with holes or sheaves to reeve signal halyards; also a temporary or emergency place for a lookout.

Origin

• "Main" refers to the mainmast, whereas a truck on another mast may be called (on the mizzenmast, for example) "mizzen-truck".