plug-in

Short definition from Wiktionary

Adjective

1. 1
   Designed to be plugged into an electrical power outlet or circuit.
2. 2
   Able to be extended with further components in a modular fashion.

Noun

1. 1
   Anything that plugs into something.
2. 2
   A module or device that interacts with another to add a specific feature or function.
3. 3
   An electric vehicle that can be recharged from an external power source.
4. 4
   An air freshener that can be charged by connecting it to the mains power supply.

Verb

1. 1
   To connect (an electrical device) to a plug socket.
2. 2
   To familiarize and integrate (a person) into an organization.
3. 3
   To replace a variable with a number in order to solve an equation.
4. 4
   To input or enter (data).
5. 5
   To become involved in something.