定长 dìngcháng fixed length Origin Definitions Defs Strokes Stroke Words Sentences Sents 1 sentence 圆是平面上到定点距离等于定长的点的轨迹。 yuán shì píngmiàn shàng dào dìngdiǎn jùlí děngyú dìngcháng de diǎn de guǐjì. A circle is the locus of points in a plane that are at a fixed distance from a fixed point. Source: Dong Chinese Dictionary