凸とつ面めんとつめんじ字FuriganaMeanings1noun, noun which may take the genitive case particle 'no'convex surface; convexTechnical term used in geometry, optics, and engineering to describe a surface that curves outward. Often used attributively with の.このレンズは凸とつ面めんになっている。This lens has a convex surface.
