Reverie; fantasy (5)
I believe the answer is:
dream
I believe this is a double definition.
'reverie' is the first definition.
(I've seen this in another clue)
'fantasy' is the second definition.
(I know that dream is a type of fantasy)
(Other definitions for dream that I've seen before include "Illusion" , "Cherished hope; reverie" , "Vision, fantasy" , "Switch off" , "Cherished hope or ideal" .)