obsolete 1. a soil characteristic of a large area or zone 2. one of the three primary subdivisions (orders) in soil classification as used in the United States —note 1. the term is not used in the current US system of soil taxonomy; zonal soils include Brown Podzol, Chernozem, Chestnut, Gray-Brown Podzol, Laterite, Latosol, Podzol, Prairie, and Red-Yellow Podzolic —see soil orderThis definition last updated 08/26/2008