1To flash or flicker (as light or lightning); to gleam briefly.
夜空に稲妻がひらめいた。
Lightning flashed across the night sky.
金属の表面が光を受けてひらめいた。
The metal surface gleamed as it caught the light.
遠くでカメラのフラッシュがひらめいた。
A camera flash flickered in the distance.
2To flutter or wave (as a flag); to undulate or ripple in the wind.
運動会で校旗が風にひらめいていた。
The school flag was fluttering in the wind at the sports day.
のぼりが通り沿いでひらめいている。
Banners are fluttering along the street.
3To have an idea flash into one's mind; to suddenly come up with a thought or insight.
試験中にいい解き方がひらめいた。
A good way to solve it suddenly came to me during the exam.
会議で彼女の意見にひらめきがあった。
She had a sudden insight during the meeting.
新しい商品のアイデアがひらめいたのでメモした。
An idea for a new product flashed into my mind, so I jotted it down.