Hidden family fortune detailed end of inheritance (11)
I believe the answer is:
clandestine
'hidden family fortune' is the definition.
The answer and definition are not the same part of speech. However, adjectives and past participle verbs occasionally define each other.
'detailed end of inheritance' is the wordplay.
I cannot quite see how this works, but
an anagram of 'end' is 'nde' which is present in the answer.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for clandestine that I've seen before include "Surreptitious" , "Concealed" , "through the backdoor" , "Private" , "backroom" .)