Foreshadowing something bad (7)
I believe the answer is:
ominous
'foreshadowing something bad' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for ominous that I've seen before include "Looking like trouble coming" , "Portentous" , "US moon I find threatening" , "Looking like trouble ahead" , "Foreboding, threatening" .)