Word

ほたる、ホタル
firefly (Luciola cruciata); lightning bug; glowworm
Word

蛍光

螢光
けいこう
fluorescence
Word

蛍光ペン

螢光ペン
けいこうペン
highlighter; highlighter pen
Word

蛍光灯

蛍光燈、螢光灯、螢光燈
けいこうとう
fluorescent lamp; fluorescent light; person who is slow to react; someone slow on the uptake
Word

蛍石

螢石
ほたるいし、けいせき
fluorite; fluorspar
Word

蛍雪

螢雪
けいせつ
diligence in studying (e.g. continuing to study even in such poor light as offered by a firefly or that reflected by snow); diligent study
Word

螢火

蛍火
けいか、ほたるび
light of a firefly