I. ˈ ̷ ̷ˌlüm noun
Etymology: Middle English heirlome, from heir + lome implement, tool — more at loom
1. : a piece of property (as a deed or charter) that is viewed by law or special custom or will or settlement as an inseparable part of an inheritance and is so inherited with the inheritance
2. : something having special monetary or sentimental value or significance that is handed on either by or apart from formal inheritance from one generation to another
the pin is a family heirloom
a spiritual heirloom that must, at all cost, be preserved intact — Edward Sapir
II. noun
: a horticultural variety that has survived for several generations usually due to the efforts of private individuals
a salad made with heirloom tomatoes
heirloom seeds