Married constituent imbibing beer is a villain (10)
I believe the answer is:
malefactor
'villain' is the definition.
(thesaurus)
'married constituent imbibing beer' is the wordplay.
'married' becomes 'm'.
'constituent' becomes 'factor' ('factor' can be a synonym of 'constituent'**).
'imbibing' means one lot of letters goes inside another.
'beer' becomes 'ale' (I've seen this before).
'm'+'factor'='mfactor'
'mfactor' going around 'ale' is 'MALEFACTOR'.
'is a' acts as a link.
(Other definitions for malefactor that I've seen before include "Wrongdoer" , "culprit?" , "Sinner" , "Criminal, evil-doer" , "bad person?" .)