A twinkling is an instant, or a flickering of light. In the twinkling of an eye, a twinkling of stars, gone in a twinkling.
The time sense survives almost entirely in the phrase in the twinkling of an eye, which comes from the King James Bible. The light sense is what stars do — the flicker is the atmosphere moving, which is why planets do not twinkle.
1nountwinklingAn instant, or a flickering of light.
“We could see the twinkling of the town's lights across the dark valley.”
twinkling is an instant, or a flicker.
Twinkle plus -ing. Twinkle is Old English twinclian, to blink or wink.
Middle English
twynkelynge
English, today
twinkling
From Middle English twynkelynge, equivalent to twinkle + -ing.
Etymology from Wiktionary, CC BY-SA