螢

A phono-semantic compound:

虫 (insect) — semantic component, classifies it as an insect

𤇾 (yíng, “lamp / light”) — phonetic component, supplies the sound and reinforces the idea of light

This dual structure makes the meaning especially transparent “a light-giving insect.”

螢 is a literary / classical character. In modern Korean, 반딧불이 is almost always written in native Korean, not with Hanja.

The compounds below appear mainly in classical texts, literature, idioms, and scholarly writing.

형화 (螢火) — firefly light; firefly glow

형광 (螢光) — fluorescence; luminescent light

Idiomatic Expressions:

형설지공 (螢雪之功) — achievement gained through hardship and diligence

낭형 (囊螢) — collecting fireflies to study by their light

Related Characters (Light & Insects)

燈 — lamp (artificial light)

炎 — flame (fire-based light)

虫 — insect (semantic category)

光 — light (abstract light)

䗾 (rare, historical)