Smith's block found in Roman villa (5)
I believe the answer is:
anvil
'smith's block' is the definition.
(I've seen this in another clue)
'in roman villa' is the wordplay.
'in' indicates a hidden word.
'ANVIL' is hidden in the letters of 'roman villa'.
'found' acts as a link.
(Other definitions for anvil that I've seen before include "Heavy block on which to hammer metal" , "Block for hammering" , "Smithy's block" , "Forging block" , "Heavy metal block in forge" .)