Dreamer (8)
'dreamer' is the definition.
(synonyms)
This is the entire clue.
(Other definitions for escapist that I've seen before include "One who tries to avoid the harsh world" , "One indulging in fantasy" , "I fantasise" , "One who tries to avoid reality" , "Dreamer, wishful thinker" .)
'dreamer' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for walter mitty that I've seen before include "Thurber's fictional fantasist" , "fictional character" , "Thurber character - one who fantasises" , "Dreamer" , "fanciful sort" .)