Essential and Plug-in

Essential noun - Something necessary, indispensable, or unavoidable.

Plug-in and essential are semantically related In some cases you can use "Plug-in" instead a noun "Essential".

Nearby Words: essence, essentially, essentiality

Plug-in noun - A printed circuit that can be inserted into expansion slots in a computer to increase the computer's capabilities.

Essential and plug-in are semantically related in element topic. Sometimes you can use "Essential" instead a noun phrase "Plug-in".