Snare wild one, so (5)
I believe the answer is:
noose
'snare' is the definition.
('noose' can be a synonym of 'snare')
'wild one so' is the wordplay.
'wild' is an anagram indicator.
'one'+'so'='oneso'
'oneso' anagrammed gives 'NOOSE'.
(Other definitions for noose that I've seen before include "Loop for catching animals" , "old execution method" , "Loop - snare" , "form of punishment" , "Hangman's running loop" .)