Compulsion to turn gown out (6)
I believe the answer is:
duress
'compulsion' is the definition.
(as in doing something under duress)
'turn gown out' is the wordplay.
'turn' becomes 'u' (a 'U-turn' is a kind of turn).
'gown' becomes 'dress' (gown is a kind of dress).
'out' indicates putting letters inside.
'u' put into 'dress' is 'DURESS'.
'to' is the link.
(Other definitions for duress that I've seen before include "Coercion, compulsion" , "Compulsory force or threat" , "Restraint" , "Illegal coercion" , "Use of force or threats to get something" .)