Extravagant lord with a pig? That's novel (8)
I believe the answer is:
prodigal
'extravagant' is the definition.
(I know that extravagant can be written as prodigal)
'lord with a pig? that's novel' is the wordplay.
'with' says to put letters next to each other.
'that's novel' indicates anagramming the letters (letters in a new or novel order).
'lord'+'a'+'pig'='lordapig'
'lordapig' is an anagram of 'PRODIGAL'.
(Other definitions for prodigal that I've seen before include "overspending" , "Extravagant like Biblical son" , "Extravagant - lavish" , "Recklessly wasteful or extravagant" , "Profligate" .)