A lucrative business or product. Primarily heard in UK, Australia. That mobile dating app has proved to be a real money-spinner for the developer—it's making them more money than anything else they've launched before.

A small propeller-shaped toy designed to be spun atop one's fingertip. Ostensibly a device to help people with attention deficit disorder or attention deficit hyperactivity disorder increase their focus, the fidget spinner became popular with schoolchildren and those who use it to try to ease anxiety or restlessness. Ever since I got my son a fidget spinner, he's had an easier time paying attention in class, but the school is considering banning them as a distraction.