The term daimyo (kanji: 大名) means "feudal lord" in English. It is written だいみょう in hiragana. It may also be rendered in English as daimyō or daimyou. It's pronounced roughly like "dime-yo".
This word refers specifically to the feudal lords of the late Heian and Kamakura eras. 大 means large or great (in the sense of excellence). 名 is short here for myoshu (名主), roughly translated as steward. The daimyo was steward over a myoden (名田), which is roughly translated as manor.
Myo is one of the Chinese readings of 名. The Japanese reading is na, in which guise it means name. Either na or, more commonly, namae (名前) can be used for “name”.