1. return to somebody with additional news or information
I will get back to you on that
To 'get back to someone' means to contact someone for a second time with an update or with further information or news. You will hear this expression used often in professional situations when someone doesn't immediately have an answer to something but promises to 'get back to someone' with the information or answer they need at a later time. "I'm afraid Mr Shi isn't available at the moment but I will make sure he gets back to you." "I need to check those details with our supplier, can I get back to you on that?"