In Cochin, a townhouse screens a film (9)
I believe the answer is:
chinatown
'a film' is the definition.
(I've seen this before)
'in cochin a townhouse screens' is the wordplay.
'in' indicates the answer is hidden within the clue.
'CHINATOWN' is hidden in the letters of 'cochin a townhouse screens'.
(Other definitions for chinatown that I've seen before include "Ethnic city quarter" , "District where most are of Far Eastern origin" , "film by Polanski" , "where Asians live" , "London area north of Leicester Square" .)