Middle digits dimwits partly raised (5)
I believe the answer is:
midst
'middle' is the definition.
(thesaurus)
'digits dimwits partly raised' is the wordplay.
'partly' says the answer is hidden in the clue.
'raised' says the letters should be written backwards.
'tsdim' is hidden in the letters of 'digits dimwits'.
'tsdim' in reverse letter order is 'MIDST'.
(Other definitions for midst that I've seen before include "Blue dye; rainbow hue" , "Centre" , "Thick (of things)" , "Central part" , "Among, amid" .)