How to say "convex" in Japanese
Choosing the right word
- 凸とつna-adjective, no-adjectiveThe bare element meaning 'convex', glossed simply as convex. It is not normally used on its own as a standalone word for 'convex'; it essentially appears as the convex-side counterpart to 凹 in convex-concave descriptions.
- 中高なかだかno-adjectiveCovers 'convex' in the sense of something bulging or rising toward the middle. Suited to describing shapes whose center is higher or fuller than the edges, such as a gently arched line or surface.
- prenominal modifierThe katakana loanword for convex. It is mainly heard in technical or commercial contexts, especially optics and lenses, where English-derived vocabulary is usual.
- 凸形とつけいno-adjectiveMeans convex as a shape — something that bulges outward. Its broader glosses 'cuspid' and 'gibbous' show it covers pointed and bulging forms as well; use it when naming the shape itself rather than a surface.
- 凸面とつめんno-adjectiveStrictly 'convex surface', and the usual choice when 'convex' refers to a curved outward-facing surface, as of a lens or mirror. It is the most direct way to say 'convex' in optical and geometric contexts.
For a convex surface use 凸面; 凸形 describes something convex in shape; 凸 is the bare morpheme; 中高 describes a raised middle; 「コンベックス」 is the loanword for optical/technical convex.
Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only
Japanese equivalents
