A term used to describe one that is looking sexy
Damn girl, you're lookin flash.
Fashionable, expensive, impressive.
A Brit can see your Porsche and say, "That's a flash car."
This a shortcut for False eyelashes, False eyelashes are something girls and other genders glue onto their eyelids for their eyelashes to look bigger / etc for any purpose.
Can you buy me some flashes from the store and some flash glue? / Anita
Yeah OfCourse i can girl i gotchu, is this your first-time wearing flashes / Cornelia
"Did you see that streak?" "Of course you didn't, that was the Flash."
" I kept telling her to leave me alone and she wouldn't so I flashed"