The Japanese prefix '第 (だい)' is used to indicate ordinal numbers, similar to '1st', '2nd', '3rd' in English. It is commonly attached to numbers to denote order, rank, or sequence. For example: first place「第一位」(だいいちい). Second chapter「第二章」(だいにしょう). Third time「第三回」(だいさんかい). This prefix is often used in formal or structured contexts, such as academic chapters, competition rankings, or event iterations. It is important to note that '第' is always followed by a number and does not stand alone as a word.