Dictator's demand for massage (5)
I believe the answer is:
knead
'for massage' is the definition.
(synonyms)
'dictator's demand' is the wordplay.
'dictator's' indicates a 'sounds like' (homophone) clue (as somebody dictating would pronounce the word).
'demand' becomes 'need' (synonyms).
'need' is a homophone of 'KNEAD'.
(Other definitions for knead that I've seen before include "Massage - naked (anag)" , "Work dough or massage flesh" , "Somehow work in" , "Work (dough/clay)" , "Work (dough) into mass" .)