plug-in

Meaning

adjective Designed to be plugged into an electrical power outlet or circuit.
a plug-in hand drill
adjective Able to be extended with further components in a modular fashion.
noun Anything that plugs into something.
noun A module or device that interacts with another to add a specific feature or function.
noun An electric vehicle that can be recharged from an external power source.
noun An air freshener that can be charged by connecting it to the mains power supply.