godan verb (-ku), intransitive verb
Describes a sudden, brief light such as lightning, a sparkle, or a gleam. Often used for natural phenomena or shiny objects.
遠くで稲妻がひらめいた。
Lightning flashed in the distance.
水面が日の光でひらめいている。
The water surface is glittering in the sunlight.
godan verb (-ku), intransitive verb
Used for flags, curtains, or other flexible things moving lightly in the wind or water. Less common than the light-flash sense.
旗が風にひらめいている。
The flag is fluttering in the wind.
godan verb (-ku), intransitive verb
flash into one's mind; come to one suddenly
Metaphorical use: an idea or inspiration strikes suddenly, like a flash of light. Very common in everyday speech.
いいアイデアがひらめいた。
A good idea flashed into my mind.
突然、解決策がひらめいた。
Suddenly, a solution came to me.