1to twinkle, flicker, or waver (used for stars, flames, lights, etc.).
夜空に無数の星が瞬いていた。
Countless stars were twinkling in the night sky.
ろうそくの炎が風で瞬いた。
The candle flame flickered in the wind.
古い蛍光灯が瞬いて作業に集中できない。
The old fluorescent lamp is flickering and I can't concentrate on my work.
2to blink (one's eyes); to wink; to bat one's eyes.
驚いて彼は何度もまばたいた。
Surprised, he blinked several times.
強い光が差し込んで目を瞬かせた。
A strong light shone in and I had to blink my eyes.
彼女は冗談で片目を瞬いた。
She winked with one eye as a joke.