Definition of "aflash"

Soon we could see the innumerable banners fluttering, and then the sun struck the sea of armor and set it all aflash. Yes, it was a fine sight; I hadn’t ever seen anything to beat it.

1889, Mark Twain, chapter 43, in A Connecticut Yankee in King Arthur's Court‎, New York: Charles L. Webster, pages 553-554

From the ceiling a screen folded down, its face aflash with myriad numbers, grids, and graphs.

1976, Samuel R. Delany, chapter 4, in Triton‎, New York: Bantam, page 152

He stroked his small, dark, squarish jaw, and lit up a cigarette, although the no smoking light had been aflash for at least fifteen minutes.

1980, Don DeLillo (as Cleo Birdwell), Amazons, New York: Holt, Rinehart and Winston, Part 2, Chapter 8, pp. 171-172