twinkling

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. The act of blinking.
2. n. A blink or twinkle: the twinkling of a starry sky.
3. n. The time it takes to blink once; an instant: disappeared in the twinkling of an eye.

Century Dictionary and Cyclopedia

1. n. The act of one who or that which twinkles; especially, a quick twitching or fluttering movement of the eye; a wink.
2. n. The phenomenon of scintillation of the fixed stars, consisting of fluctuations of light and of color at the rate of from fifty to a hundred per second. ; The fluctuations of light did not escape the notice of the ancients; those of color were noticed by Robert Hooke in 1665. The phenomenon was, without any reason at all, generally supposed to have its origin in the eye, until William Nicholson, the chemist, showed in 1813 that, if the image of a twinkling star was stretched out into a ribbon by an irregular movement of the telescope, the fluctuations would appear as variations of light and color along this ribbon. Charles Dufour, in 1856, published the following generalizations of his observations, now known as Dufour's laws:
3. n. The time required for one twinkle or wink, as of the eye; a flash; hence, a very short time.

Wiktionary

1. adj. Sparkling intermittently.
2. n. A shining with fast intermittent light.
3. n. The time it takes to blink the eyes.
4. v. present participle of twinkle.

GNU Webster's 1913

1. n. The act of one who, or of that which, twinkles; a quick movement of the eye; a wink; a twinkle.
2. n. A shining with intermitted light; a scintillation; a sparkling.
3. n. The time of a wink; a moment; an instant.

WordNet 3.0

1. adj. shining intermittently with a sparkling light
2. n. a very short time (as the time it takes the eye to blink or the heart to beat)