凹透镜 āotòujìng concave lens Definitions Defs Origin Strokes Stroke Words Sentences Sents 凹 āo adjectivenoun concave concave; sunken; dented; low-lying透镜 透鏡 tòujìng lens An optical component made of transparent material like glass or crystal that refracts light; usually classified into 凸透镜 tūtòujìng and 凹透镜 āotòujìng
