A power adapter is a device that allows you to connect electrical devices to a power source, such as a wall socket. It helps convert the electrical current from the source to a suitable level for the device to function properly. Full definition
When running off a wall outlet with the USB - C power adapter plugged directly into the Switch, it charges even faster. (fortune.com)
Once you've downloaded the app, plug the included power adapter into a power outlet, and plug the other end into the input on the bottom of the speaker. (androidauthority.com)
If you don't have a USB port on your TV, the kit includes a USB power adapter for use with any standard wall outlet. (antennasdirect.com)