I. heir ‧ loom 1 /ˈeəluːm $ ˈer-/ BrE AmE noun [countable]
[ Date: 1400-1500 ; Origin: heir + loom 'tool' (10-19 centuries) ]
a valuable object that has been owned by a family for many years and that is passed from the older members to the younger members:
a family heirloom
II. heirloom 2 BrE AmE adjective [only before noun]
an heirloom vegetable or plant is one of a kind that was first grown many years ago, and has now become rare or unusual SYN heritage :
They sell many kinds of heirloom seeds.