noun
glow of a firefly
Refers to the light emitted by fireflies, often used in poetic or seasonal contexts.
夏の夜、川辺に蛍火が揺れていた。
On a summer night, the glow of fireflies flickered by the riverside.
noun
nearly extinguished fire; embers
Describes a fire that is about to go out, leaving only faint embers. Often used metaphorically for something fading.
焚き火は蛍火のように消えかかっていた。
The bonfire was dying down to embers like a firefly's glow.
Out-dated kanji form; 蛍 is the modern standard.
Compound of 蛍 (hotaru, 'firefly') and 火 (hi, 'fire'), with rendaku voicing of 火 to び. The reading けいか is the on'yomi reading, used in more formal or literary contexts.