American organisation holds people up in darkened room (6)
I believe the answer is:
cinema
'darkened room' is the definition.
(lights in a cinema are dimmed during a film)
'american organisation holds people up' is the wordplay.
'american organisation' becomes 'cia' (CIA is an example. I am not sure about the 'american' bit.).
'holds' indicates putting letters inside.
'people' becomes 'men' (men are people).
'up' says the letters should be written in reverse (in down clue: letters go upwards).
'men' back-to-front is 'nem'.
'cia' enclosing 'nem' is 'CINEMA'.
'in' is the link.
Can you help me to learn more?
(Other definitions for cinema that I've seen before include "Picture house" , "The big screen" , "place for pictures" , "Movies, pictures" , "Movie theatre" .)