凸凹
でこぼこ · dekoboko · JLPT N2 · noun
unevenness
🪨 凸 = bump out + 凹 = dip in; both together = unevenness
でこぼこ pairs でこ (raised bump, 凸) with ぼこ (sunken hollow, 凹). The sound-pair marks a surface that alternates between raised and sunken parts.
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').
凹 — pictograph of a concave shape
凹 is a pictograph depicting a concave or sunken shape, with its outline literally dipping inward in the middle. It is one of a famous pair with 凸 (convex), and the character itself visually shows the meaning 'concave, hollow, dented.' It has no phonetic component — the form is the meaning.