Radio/ˈreɪdiəʊ/ Definition 1 of 5Pro Tip 1/3Everyday Use Radio as a device is common in daily life for entertainment or news. Turn on the radio to check the weather forecast. Pro Tip 2/3Background Sound Radios often play in the background while people do other activities. He likes having the radio on while he studies. Pro Tip 3/3Portable Radios come in portable sizes so you can carry them around. She took her portable radio to the picnic.