凸
tū · HSK 7
to stick out
Pictographic: the glyph itself bulges upward, a bump sticking out = convex
凸 is one of Chinese's most literal characters, its outline traces a shape with a raised middle section. Pairs with its opposite 凹 (āo, concave/dented in). Together 凸凹 means uneven or bumpy.
凸 — pictograph of a convex/protruding shape
凸 is a modern pictographic character depicting a shape that protrudes or bulges outward, with the central stroke rising above the surrounding outline. It has no traditional radical-phonetic structure; the form itself visually conveys the meaning 'convex' or 'sticking out.' It pairs with its mirror 凹 ('concave').