Add-on and Companion

Add-on noun - Something that is not necessary in itself but adds to the convenience or performance of the main piece of equipment.

Companion and add-on are semantically related. In some cases you can use "Companion" instead a noun phrase "Add-on".

Companion noun - A person frequently seen in the company of another.

Add-on and companion are semantically related. Sometimes you can use "Add-on" instead a noun "Companion".

Nearby Words: companionable, companionship, companioned