from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A very black topsoil, rich in humus, typical of cool to temperate semiarid regions, such as the grasslands of European Russia.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A fertile black soil containing a very high percentage of humus (3% to 15%) and high percentages of phosphoric acids, phosphorus and ammonia.
from The Century Dictionary and Cyclopedia
- n. The local name of a black earth of extraordinary fertility, covering at least 100,000,000 acres, from the Carpathian to the Ural mountains, to the depth of from 4 to 20 feet, and yielding an almost unlimited succession of similar crops without preparation.
Russian chernozëm : chërnyĭ, black + Old Russian zemĭ, earth; see dhghem- in Indo-European roots.(American Heritage® Dictionary of the English Language, Fourth Edition)
From Russian чернозём (černozjóm), "black soil", letter "ё" is usually written as "е" in Russian, more accurately transliterated as "chernozyom", also cf. Черноземье (Černozémʹje) where "ё" is changed to "е". (Wiktionary)