ye·do·ma 
(yĕdə-mə, yə-dō-)
(yĕdə-mə, yə-dō-)n.
A type of permafrost consisting primarily of loess and organic material, believed to sequester large amounts of carbon.
[Archaic and regional Russian yedoma, backwoods, a place that lacks reindeer, yedoma, of Nenets origin; akin to Nenets yada, on foot (since the Nenets use reindeer to draw sledges and without them go on foot).]