A garth is garden, yard, or field, especially one that is enclosed. It comes from the Old Norse garðr, meaning a garden, yard, or fence, and having been around a long time is has become applied to many different situations; an orchard may be called an applegarth, a stand of willows may be called a willow-garth, a barnyard garden may be a barngarth, a weir may be a fishgarth. These various terms have mostly disappeared from common usage, but still live on in family names and place names; it has recently come into usage as a given name.
These days, if one refers to a garth one probably means a courtyard or formal garden surrounded by covered walks (cloisters). These are not common, but are sometimes found in churches and large country houses. In these cases, one usually refers to the cloister as the architectural feature, and the fact that it surrounds a garth is generally ignored unless one is a wordnerd or a gardener.
Garðr was in common usage in northern and western England, where the invasions of the Viking age left a large footprint; other words common in place names of Old Norse origin include kirk, scale, fell, beck, tarn, gill, breck, holm, slack, thwaite, and wray.