This site will be taken down March 31st, 2026.

This was not an easy decision to make. For the last couple years, I have been struggling to find motivation for this site and to keep up with basic maintenance and security updates. With the rise of AI and more sophisticated tools, the usefulness of sites like this is questionable and traffic has nose-dived. I just don't have it in me to keep doing this. Thank you all for 10 years of support!

Zach

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

蛍袋

ほたるぶくろ
bellflower
Word

蛍光物質

けいこうぶっしつ
fluorescent substance; phosphor
Word

蛍石

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

蛍雪の功

けいせつのこう
the fruit of diligent study
Word

螢火

蛍火
けいか、ほたるび
light of a firefly
Word

蛍藺

ほたるい、ホタルイ
Scirpus hotarui (species of bulrush)
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