In its original acceptation, it signified the proprietor of a heritable subject, but, in the law relating to parish government, the term was confined to such proprietors of lands or houses as were liable, as written in their title deeds, for the payment of public burdens, such as the minister's stipend, manse and glebe assessments, schoolmaster's salary, poor rates, rogue-money (for preventing crime) as well as road and bridge assessments, and others like public and county burdens or, more generally, cess, a land tax.
For example, in the early 20th century the heritors of the Highland Parish of Crathie and Braemar were the estates of Mar Lodge, Invercauld, Balmoral, and Abergeldie.
Historically, land-holding in Scotland is feudal in nature, meaning that all land is technically "owned" by the Crown, which, centuries ago, gave it out – feued it – to various tenants-in-chief in return for specified services or obligations.
Similarly, these tenants-in-chief gave parcels of land out to lesser "owners", and the resulting reciprocal obligations too became financial – feudal dues – or notional.
However, those who held their land without limit of time – that is, only had a ceremonial or ancient financial obligation towards their notional "superiors" – were distinguished from others and were called heritors.