凹凸 āotū concave-convex Definitions Defs Origin Strokes Stroke Words Sentences Sents 1 sentence 这种地板通过凹凸的沟槽进行拼接。 zhè zhǒng dìbǎn tōngguò āo tū de gōu cáo jìnxíng pīnjiē. This flooring is joined using tongue and groove joints. Source: Dong Chinese Dictionary