Flex
Gen Z SlangDefinition
To ostentatiously show off or boast, especially by flaunting wealth, status, or achievements; also the act of such display.
Examples
"He pulled up in a rented Lambo just to flex on his ex."
"Posting that $10k watch on your story was such a flex."
"Weird flex, but okay—bragging about your 12-hour workday like it's a prize."