noun
middle of a field; middle of a country; field of contest
Literary or formal word for a central plain or heartland, often used in historical or poetic descriptions of a region. The 'field of contest' sense is rare and figurative, implying a central arena of struggle.
彼は広大な中原を馬で駆け抜けた。
He galloped across the vast central plain on horseback.
その国の中原は
The heartland of that country is known as fertile farmland.