萤火 yínghuǒ firefly glow Definitions Defs Origin Strokes Stroke Words Sentences Sents 萤火虫 yínghuǒchóng firefly firefly; glowworm; lightning bug雪窗萤火 xuěchuāngyínghuǒ studying under difficult conditions To study diligently in spite of hardship; refers to the stories of Sun Kang, who read by reflected snow light, and Che Yin, who studied by the light of fireflies