光こう学がくこうがくCommon wordFreq.FrequencyTop 10,000Meanings1nounopticsRefers to the scientific study of light and its behavior. Used in academic, technical, and everyday contexts.彼かれは大だい学がくで光こう学がくを専せん攻こうしている。He is majoring in optics at university.光こう学がく機き器きの進しん歩ぽは目め覚ざましい。The progress of optical instruments is remarkable.