Sonnet preposition (3)
I believe the answer is:
ere
'sonnet preposition' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ere that I've seen before include "Before (lit.)" , "Before, poetically" , "Before (in time)" , "Archaic word for before - a palindrome" , "Before (poetic)" .)