Definitions

1. verb

to flash upward or suddenly appear, especially in a brief, vivid, or intense manner

“The fireworks upflashed across the night sky.”

2. noun

a brief, vivid, or intense flash upward

“The upflash of light blinded me momentarily.”

3. verb, archaic

to rise suddenly, especially in a flash of anger or emotion

“The prisoner upflashed in a rage when he heard the verdict.”