godan verb (-su), transitive verb
Used for waving or showing something quickly and conspicuously, such as a weapon, a card, or a piece of evidence. Often implies a sudden, brief motion.
犯人はナイフをひらめかして逃げた。
The culprit brandished a knife and fled.
彼は証拠の写真をひらめかせた。
He flashed the photo as evidence.