Fantasy spaces I'm developing (8)
I believe the answer is:
escapism
'fantasy' is the definition.
(I've seen this before)
'spaces i'm developing' is the wordplay.
'developing' indicates anagramming the letters (letters developed into a new form).
'spaces'+'im'='spacesim'
'spacesim' anagrammed gives 'ESCAPISM'.
(Other definitions for escapism that I've seen before include "An inclination to retreat from unpleasant realities through diversion or fantasy" , "Tendency to avoid reality" , "Mass epic (anag.)" , "Avoiding life's realities by indulging in fantasies" , "Preferring fantasy to the realities of life" .)