Within the house is the scoundrel (7)
I believe the answer is:
villain
'the scoundrel' is the definition.
(synonyms)
'within the house' is the wordplay.
I cannot quite see how this works, but
'within' could be 'in' and 'in' is found within the answer.
'house' could be 'villa' (villa is a kind of house) and 'villa' is found in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
'is' acts as a link.
Can you help me to learn more?
(Other definitions for villain that I've seen before include "He may rob you" , "Bad person in story/play" , "Criminal person" , "Evil-doer" , "Principal fictional baddie" .)