円えん錐すい台だいえんすいだいじ字FuriganaMeanings1nountruncated cone; frustum of a coneGeometric term for a cone whose top has been cut off by a plane parallel to the base. Used in mathematics and engineering.円えん錐すい台だいの体たい積せきを計けい算さんする公こう式しきを覚おぼえていますか。