a beam laid along the edge where two sloping sides of a roof meet at the top; provides an attachment for the upper ends of rafters
同义词：ridge, rooftree
ridgepole详细解释
ridge.pole n.（名词）A horizontal beam at the ridge of a roof to which the rafters are attached.主梁：椽被附在屋顶边沿的横梁The horizontal pole at the top of a tent.篷梁：帐篷顶部的水平柱子
