几何光学 jǐhéguāngxué geometric optics Origin Definitions Defs Strokes Stroke Words Sentences Sents 几何 幾何 jǐhé geometry geometry; often used as a short form for 几何学 jǐhéxué光学 光學 guāngxué noun optics the branch of physics that deals with the properties, behavior, and nature of light