Before the real part (3)
I believe the answer is:
ere
'before' is the definition.
(poetic term for 'before')
'real part' is the wordplay.
'real' becomes 'e' (e is a kind of real).
'part' becomes 're' (re is a kind of part).
'e'+'re'='ERE'
'the' is the link.
(Other definitions for ere that I've seen before include "Before, poetically" , "One who steals" , "Before (in time)" , "Archaic word for before - a palindrome" , "Old word for before" .)