flash on

1. To abruptly turn on, as of lights. As the man laughed manically, the lights in the haunted house flashed on, and we all ran out, screaming. I was worried the power would be out for a while, but the lights flashed on in less than 30 minutes. Thankfully, the overhead lights flashed on as I was feeling around for a flashlight.

2. To illuminate someone or something. I repositioned my lamp so that it flashed on the things I'd dropped behind my bureau. Dude, if that police spotlight flashes on us, we're done! I was startled when my headlights flashed on a deer crossing the highway.

3. slang To think of or recall something. It took some time, but we finally flashed on a solution to that problem. Please tell me you've flashed on that guy's name because I can't think of it at all. I need to flash on an offer they'll actually accept. How can I sweeten the deal for them?

flash on something

in. to remember something suddenly and vividly. I was trying to flash on it, but I couldn’t bring it to mind.