noun
right cylinder
A cylinder whose axis is perpendicular to its bases. Used in geometry.
直円柱の体積は底面積×高さで求められる。
The volume of a right cylinder is found by multiplying the base area by the height.
円柱 is a general cylinder, which may be oblique. 直円柱 specifically means a right cylinder.
Compound of 直 (straight, right) and 円柱 (cylinder).