八はっ角かく錐すいはっかくすいMeanings1nounoctagonal pyramidA geometric solid with an octagonal base and triangular faces meeting at a point.数すう学がくの授じゅ業ぎょうで八はっ角かく錐すいの体たい積せきを計けい算さんした。We calculated the volume of an octagonal pyramid in math class.
