Force gown to take turn (6)
I believe the answer is:
'force' is the definition.
(I know that duress is a type of force)
'gown to take turn' is the wordplay.
'gown' becomes 'dress' (gown is a kind of dress).
'to take' means one lot of letters goes inside another (inserted letters are taken in).
'turn' becomes 'u' (a 'U-turn' is a kind of turn).
'dress' enclosing 'u' is 'DURESS'.
(Other definitions for duress that I've seen before include "Use of force or threats to get something" , "Excessive pressure" , "Compulsory force or threat" , "Constraint, Compulsion" , "Constraint, coercion" .)