Dismounts for the illuminations (6)
I believe the answer is:
lights
I believe this is a double definition.
'dismounts' is the first definition.
('light' can be a synonym of 'dismount')
'illuminations' is the second definition.
('light' can be a synonym of 'illumination')
'for the' is the link.
(Other definitions for lights that I've seen before include "Sources of illumination" , "Innards" , "See 11" , "Comes down" , "Blackpool is known for such" .)