topmast

详细解释:n. 中桅

英语解释：

名词 topmast:

the mast next above a lower mast and topmost in a fore-and-aft rig

例句：

A platform enclosing the head of each mast of a sailing ship, to which the topmast rigging is attached.桅楼，桅盘帆船上包围着所有帆头的平台，顶桅索具就加结于其上