Gnarled thing, stout stick in disco (9)
I believe the answer is:
nightclub
'disco' is the definition.
(I've seen this before)
'gnarled thing stout stick' is the wordplay.
'gnarled' indicates an anagram (I've seen this in other clues).
'stout stick' becomes 'club' (large stick).
'thing' with letters rearranged gives 'night'.
'night'+'club'='NIGHTCLUB'
'in' is the link.
(Other definitions for nightclub that I've seen before include "Place open late for entertainment, food and drink" , "one of the high spots" , "disco" , "Entertainment centre" , "cabaret" .)