Snare returned before long to head of estate (5)
I believe the answer is:
noose
'snare' is the definition.
('noose' can be a synonym of 'snare')
'returned before long to head of estate' is the wordplay.
'returned' is a reversal indicator.
'before long' becomes 'soon' (I've seen this before).
'to head of' says to take the initial letters.
The initial letter of 'estate' is 'e'.
'soon' back-to-front is 'noos'.
'noos'+'e'='NOOSE'
(Other definitions for noose that I've seen before include "A loop for the hangman" , "Loop formed by means of a slip knot" , "Loop of rope with a slipknot" , "Loop for catching animals" , "Scaffold rope" .)