Noun
yarth (uncountable)
(obsolete, UK, dialect) earth
"By the way, action takes place on Yarth, a place somewhat similar to Oerth, the setting of Greyhawk, et al. Source: Internet
It is not impossible that additional works will be contracted for in months to come, action being set on Yarth or perhaps another alternate world, Aerth. Source: Internet
The five parallel worlds of Oerth, Aerth, Uerth, Yarth and Earth were mentioned in the 3rd Edition adventure Expedition to the Ruins of Greyhawk and thus found their way into 3rd edition canon. Source: Internet
Yarth has a sprinkling of things magical, and Oerth is pure magic." Source: Internet