Daimyo (大名) is a generic term referring to a powerful Japanese feudal lord, lord of lands, subordinate only to the Shogun.
They were the powerful territorial lords in Japan, who ruled most of Japan from their vast hereditary estates from the 10th to the 19th century.
During this period, Japan was divided into several autonomous territories. They were controlled by feudal lords (daimyo), with the support of samurai. The Daimyo often hired samurai to protect their land and paid the samurai in land or food. Relatively few daimyo could pay the samurai in cash.
In the twelfth century, some daimyo were more powerful than the emperor himself. That was at least until its decline at the beginning of the Meiji period.
Meaning, DAI (大) literally means “big” and MYO means myōden (名田), which means private land.