Prep has to be done maybe (7)
I believe the answer is:
perhaps
'maybe' is the definition.
(synonyms)
'prep has to be done' is the wordplay.
'to be done' indicates anagramming the letters.
'prep'+'has'='prephas'
'prephas' anagrammed gives 'PERHAPS'.
(Other definitions for perhaps that I've seen before include "Not necessarily" , "Possibly but not certainly" , "Conceivably" , "Possibly, maybe" , "say" .)