Derived from family, yet hardier material (10)
I believe the answer is:
hereditary
'derived from family' is the definition.
I can't judge whether this definition defines the answer.
'yet hardier material' is the wordplay.
'material' indicates anagramming the letters (the letters provide the material for a new word).
'yet'+'hardier'='yethardier'
'yethardier' with letters rearranged gives 'HEREDITARY'.
Can you help me to learn more?
(Other definitions for hereditary that I've seen before include "Ancestral" , "Passed on by parents" , "passed down through generations" , "passed from generation to generation" , "Family" .)