Nantoka/凸凸tū tū凸凸 (tū tū) is a Chinese word meaning “convex on both sides (of lens); biconvex”.Meanings1convex on both sides (of lens)2biconvexCharacters in 凸凸凸tū · to stick out; protruding; convex; male (connector etc)凸tū · to stick out; protruding; convex; male (connector etc)Related words凸to stick out; protruding; convex; male (connector etc)凸显to stand out clearly; to make prominent凸出to protrude凸起convex凹凸concave or convex凸现to come to prominence凸透镜convex lens凸轮cam凹凸不平(idiom) uneven (surface); bumpy (road)凸版relief printing plate凸面convex surface凸轮轴camshaftStudy Chinese with flashcards →