Make gloomy (6)
I believe the answer is:
darken
(Other definitions for darken that I've seen before include "Grow less light" , "Make less light" , "Cast a shadow over" , "Grow blacker" , "Cloud over" .)
I believe the answer is:
darken
(Other definitions for darken that I've seen before include "Grow less light" , "Make less light" , "Cast a shadow over" , "Grow blacker" , "Cloud over" .)