CATCH ON

{v.}, {informal} 1. To understand; learn about. - Often used with "to". * /You'll catch on to the job after you've been here awhile./ * /Don't play any tricks on Joe. When he catches on, he will beat you./ 2. To become popular; be done or used by many people. * /The song caught on and was sung and played everywhere./ 3. To be hired; get a job. * /The ball player caught on with a big league team last year./