English definition of “flash”
SHINE [I, T] › to shine brightly and suddenly, or to make something shine in this way: The doctor flashed a light into my eye. Lightning flashed across the sky.
APPEAR [I, T] (also flash up) › to appear for a short time, or to make something appear for a short time: An icon flashed up on the screen.
flash by/past/through, etc › to move somewhere fast: The motorcycle flashed past us and around the corner.
flash (sb) a look/smile, etc › to look/smile, etc at someone quickly: She flashed him a smile as he came in.