Person in family tree can store nuts (8)
I believe the answer is:
ancestor
'person in family tree' is the definition.
The answer and definition can be both people as well as being singular nouns.
Maybe you can see a link between them that I can't see?
'can store nuts' is the wordplay.
'nuts' indicates an anagram (nuts can mean crazy).
'can'+'store'='canstore'
'canstore' anagrammed gives 'ANCESTOR'.
Can you help me to learn more?
(Other definitions for ancestor that I've seen before include "Antecedent, forebear" , "An escort (anag.)" , "Forefather" , "Old member of the family -no traces (anag)" , "not being of the modern generation" .)