Line the same following carbon copy (5)
I believe the answer is:
clone
'copy' is the definition.
(I know that clone is a more specific form of the action copy)
'line the same following carbon' is the wordplay.
'line' becomes 'l' (used when specifying particular lines from a poem).
'the same' becomes 'one' (I've seen this in another clue).
'following' says to put letters next to each other.
'carbon' becomes 'C' (C is the chemical symbol for carbon).
'l'+'one'='lone'
'lone' put after 'c' is 'CLONE'.
(Other definitions for clone that I've seen before include "spit" , "Not an original individual" , "Replicate" , "hacked phone" , "Person resembling someone else" .)