daimyo of the Warring States period
Historical term referring to the powerful regional lords who ruled during Japan's Sengoku period (late 15th to late 16th century).
The daimyo of the Warring States period often fought to expand their territories.
Oda Nobunaga is one of the most famous daimyo of the Warring States period.
大名 is the general term for a feudal lord in Japan, while 戦国大名 specifically refers to those who lived during the Sengoku (Warring States) period.
戦国時代 is the Warring States period itself; 戦国大名 are the daimyo who were active during that era.
Compound of 戦国 (Sengoku, 'Warring States') and 大名 (daimyo, 'feudal lord'). The term is straightforwardly descriptive of the daimyo of that historical period.