The story
From lightning + beetle, because the insects glow; whence also firefly.
Etymology from Wiktionary, CC BY-SA 4.0.
lightning beetle
Today it means: Any beetle of the family Lampyridae, which exhibit bioluminescence Full definition →
Today it means: Any beetle of the family Lampyridae, which exhibit bioluminescence Full definition →
From lightning + beetle, because the insects glow; whence also firefly.
Etymology from Wiktionary, CC BY-SA 4.0.