Capital's industrial action out of bounds (4)
I believe the answer is:
oslo
'capital's' is the definition.
(capital of Norway)
'industrial action out of bounds' is the wordplay.
'industrial action' becomes 'goslow' (when workers deliberately work slowly).
'out of bounds' indicates the central letters (the bounds or edges of the word are removed).
The central letters of 'goslow' are 'OSLO'.
(Other definitions for oslo that I've seen before include "where Ibsen lived under another name" , "Norway's capital city" , "Former Christiania" , "European capital, known until 1924 as Christiania" , "Capital city, called Kristiania until 1924" .)