noun, noun which may take the genitive case particle 'no'
convex surface; convex
Technical term used in geometry, optics, and engineering to describe a surface that curves outward. Often used attributively with の.
このレンズは凸面になっている。
This lens has a convex surface.
凸面鏡は光を広げる
A convex mirror spreads light.
convex mirror
Compound of 凸 (とつ, 'convex') and 面 (めん, 'surface'). The kanji 凸 is a pictograph of a protruding shape.