adverb, adverb taking the 'to' particle
with a momentary flash; glint; sparkle
Mimetic adverb describing a brief, sharp flash or glint of light, often used with と or as a standalone adverbial.
His eyes flashed for an instant.
Her ring gave a brief sparkle.
A star twinkled brightly.
The moment the blade flashed, he froze.
Kana-only mimetic adverb; no kanji spelling is given.
Mimetic word derived from the sound or sensation of a quick flash of light. The exact origin is uncertain.