Unoriginal article found in Roman dwelling (7)
I believe the answer is:
vanilla
'roman dwelling' is the definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.
'unoriginal article found in' is the wordplay.
'unoriginal' becomes 'villa' (I can't justify this - if you can you should give a lot more credence to this answer).
'article' becomes 'an' (indefinite article).
'found in' is an insertion indicator.
'villa' enclosing 'an' is 'VANILLA'.
Can you help me to learn more?
(Other definitions for vanilla that I've seen before include "Common ice cream flavour" , "conventional" , "Subtle flavour pod" , "Common flavour for ices" , "Ordinary" .)