Obstruct growth in deregulated housing (6)
I believe the answer is:
hinder
'obstruct' is the definition.
('hinder' can be a synonym of 'obstruct')
'growth in deregulated housing' is the wordplay.
'housing' indicates a hidden word (part of the clue houses the answer).
'HINDER' is hidden in the letters of 'growth in deregulated'.
(Other definitions for hinder that I've seen before include "Impede, keep back" , "Obstruct, create obstacle" , "Delay progress, obstruct" , "block" , "stop" .)