Sot's first gin sling (5)
I believe the answer is:
strap
'sling' is the definition.
(thesaurus)
'sot's first gin' is the wordplay.
'sot's first' becomes 's' (1st letter of 'sot').
'gin' becomes 'trap' (I've seen this before).
's'+'trap'='STRAP'
(Other definitions for strap that I've seen before include "Beat; securing band" , "Whip" , "Parts of leather belt" , "Narrow strip of leather" , "Length or loop, of leather perhaps" .)