noun
firefly; lightning bug
Refers to the insect, especially the Japanese firefly (Luciola cruciata). The term 'glowworm' is sometimes used but typically refers to a different family; in Japanese context, it can overlap.
夏の夜、川の近くでホタルが光っていた。
On a summer night, fireflies were glowing near the river.
When I was a child, I used to catch fireflies.