蛍光灯
けいこうとう · keikoutou · JLPT N2 · noun
fluorescent lamp
💡 蛍 (firefly) + 光 (light) + 灯 (lamp) = a lamp with firefly-style light
The first two characters, 蛍光, mean fluorescence, the scientific term for light emitted by a glowing substance. 灯 is the common word for lamp, so the word combines the two.
光 — fire 火 (top) + person 儿 (bottom)
Originally a pictograph of a person with fire above their head, depicting a torchbearer or the radiance from a flame. The character evolved to mean 'light' or 'brightness' in general, and by extension 'glory' and 'to shine.' The modern top component is a stylized form of 火 (fire).
灯 — fire radical 火 + ding 丁 (phonetic)
灯 is a semantic-phonetic compound: 火 'fire' gives the meaning (lamps once burned oil or flame), while 丁 hints at the sound. It is the simplified form of the traditional 燈, which used 登 as the phonetic. Today it means 'lamp' or 'light'.