plug-in
UK[ˈplʌɡ.ɪn]US[ˈplʌɡ.ɪn]
adj
Designed to be connected to a piece of electrical equipment by pushing it into a socket.
n
A piece of software that can be added to an existing computer program to give it extra features.
Morpheme Breakdown
plug
in
plug
connect
in
position
Etymology
The term 'plug-in' is a modern compound formed from two native English words. 'Plug' has a maritime origin, entering English from Middle Dutch 'plugge', meaning a stopper or bung used to seal a hole. Its meaning evolved to denote any object that fits into a socket to make a connection, especially an electrical one. The preposition/adverb 'in', from Old English, completes the concept by specifying the action of insertion or connection. The combined term first described physical electrical accessories before its meaning was extended metaphorically in computing to describe software modules that are "plugged into" a host application to extend its functionality, perfectly capturing the concept of a modular, connectable component.
Analysis
Structure: plug (connect) + in (position)
plug: Origin: Middle Dutch 'plugge' (stopper, bung). Role: The core element denoting a device for making an electrical connection.
in: Origin: Old English 'in' (preposition/adverb). Role: A particle indicating insertion, connection, or being positioned within a system.
Examples
The printer comes with a plug-in power adapter.
I downloaded a new plug-in to enhance the photo editing software.
Make sure the plug-in hybrid vehicle is fully charged.