Land held from a lord in return for service was known by which term?

Explanation

The word names the holding relationship itself, that is, land granted on condition that service is owed for it, and what it covered might be anything from one estate to a great block of territory. The word for the estate is the easiest slip to make, because an estate was very often the thing granted, but that word describes a unit of farmed land while this one describes the terms on which it is held.