Dreamer's opposite (7)
I believe the answer is:
realist
'dreamer's opposite' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for realist that I've seen before include "One who does not indulge in 20 down" , "One without illusions" , "Saltier (anag.)" , "Practical sort" , "Practical type" .)