I. verb
1.
to shoot forth light (as in rays or sparks)
lightning flashed in the sky
Synonyms: coruscate, glance, gleam, glimmer, glint, glisten, glitter, scintillate, shimmer, spangle, sparkle, twinkle
Related Word: dart, shoot; blare, blaze, burn, flame, flare, glare, glow, incandesce; blink, flicker, spark; dazzle; beam, radiate, shine
2.
Synonyms: blink 2, flicker, twinkle
3.
Synonyms: show 4, brandish, display, disport, exhibit, expose, flaunt, parade, show off, trot out
II. noun
1.
a sudden brief light
saw a flash sweep across the sky
Synonyms: coruscation, glance, gleam, glimmer, glint, glisten, glitter, quiver, scintillation, shimmer, sparkle, twinkle
Related Word: blare, blaze, flame, flare, glare, glow; flicker; beam, ray
2.
Synonyms: instant 1, breathing, crack, ||jiff, jiffy, minute, moment, second, shake, split second
Idioms: half a second ( or shake), twinkling of an eye