Priest in RC produces artefact (5)
I believe the answer is:
relic
'artefact' is the definition.
(I've seen this before)
'priest in rc' is the wordplay.
'priest' becomes 'eli' (biblical figure).
'in' indicates putting letters inside.
'eli' placed within 'rc' is 'RELIC'.
'produces' is the link.
(Other definitions for relic that I've seen before include "Long-surviving object" , "Souvenir; survival" , "Survival from an earlier time" , "Venerated memento" , "Paper craft" .)