Quick Answer: Dai-ichi is a compound modifier phrase of Japanese origin, meaning number one, or first. In kanji, "dai" is 第 and "ichi" is 一. "Dai" is also defined "ordinal number marker." It is this feature that makes the phrase a modifier, or an adjective, describing a noun, as first. Number one functions in the same way. The phrase is also written without the hyphen, as daiichi. Dai-ichi is frequently used in proper names, hence capitalized; also Dai-Ichi and occasionally Dai Ichi. There is a sound-alike common first name with different spelling.