Twinkle is a verb meaning to shine with a flickering or sparkling light.
It can also refer to a rapid twitching or movement, especially of the eyes.
The term "twinkle" is commonly used in:
1. The nursery rhyme "Twinkle, Twinkle, Little Star"
2. Describing stars or lights that flicker
3. Expressing a cheerful or mischievous expression in someone's eyes