Sickly-looking scoundrel will assert they should get house contents (10)
I believe the answer is:
cadaverous
'sickly' is the definition.
(thesaurus)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for cadaverous that I've seen before include "Unhealthy-looking" , "Ghastly" , "not looking healthy" , "Gaunt" , "Skeletal" .)