Identical copy (5)
I believe the answer is:
clone
'identical copy' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for clone that I've seen before include "Copied organism" , "Identical copy" , "Organism reproduced asexually from one ancestor, like Dolly the sheep" , "Not an original individual" , "Person who is identical to another" .)