Impulsive revolutionary less wild in embrace of virgin (9)
I believe the answer is:
premature
'impulsive' is the definition.
(thesaurus)
'revolutionary less wild in embrace of virgin' is the wordplay.
'revolutionary' is a reversal indicator.
'less wild' becomes 'tamer' (wild is the opposite of tame).
'in embrace of' means one lot of letters goes inside another.
'virgin' becomes 'pure' (synonyms).
'tamer' back-to-front is 'remat'.
'remat' put into 'pure' is 'PREMATURE'.
(Other definitions for premature that I've seen before include "not fully developed" , "Before the normal time" , "Rash" , "Occurring before the expected time" , "Too soon to cause me rapture" .)