It's passed down through a family (8)
I believe the answer is:
heirloom
'it's passed down through a family' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for heirloom that I've seen before include "Possession handed down through several generations of family" , "Long-time family possession" , "Valuable family piece" , "Cherished item passed down through generations" , "Item handed down for years" .)