Broody music featured in zombie movie (3)
I believe the answer is:
emo
'broody music' is the definition.
(emotional or broody music genre)
'featured in zombie movie' is the wordplay.
'featured in' indicates a hidden word.
'EMO' can be found hidden inside 'zombie movie'.
(Other definitions for emo that I've seen before include "Town and Court in Laois" , "Serious type of rock" , "music?" .)