Power in sacred object and a copy (7)
I believe the answer is:
replica
'copy' is the definition.
(replica is a kind of copy)
'power in sacred object and a' is the wordplay.
'power' becomes 'p'.
'in' means one lot of letters goes inside another.
'sacred object' becomes 'relic'.
'and' says to put letters next to each other.
'p' placed inside 'relic' is 'replic'.
'replic'+'a'='REPLICA'
(Other definitions for replica that I've seen before include "I parcel (anag) - reproduction" , "Facsimile" , "Exact copy or model" , "Copy original" , "Perfect copy" .)