第（だい、dai）
- No./ordinal prefix

The Japanese word 第 (だ[第]い) is a prefix that indicates ordinal numbers (first, second, third, etc.) or order. It's similar to "number" or "ordinal" in English, but it's used before the number itself. Think of it as a way to specify the position of something in a sequence. ⚫︎ It essentially means "the [number]th" or "number [number]". ⚫︎ It can also signify a series or a chapter within a larger work.

⚫︎ 第一 (だ[第]いいち) Translation: First ⚫︎ 第二 (だ[第]いに) Translation: Second ⚫︎ 第三章 (だ[第]さんしょう) Translation: Chapter Three

⚫︎ Use 第 before a number (or a numerical counter) to denote the order or sequence. ⚫︎ It’s essential for talking about ordinal positions, such as in rankings, timelines, or chapters of a book. ⚫︎ You will frequently encounter 第 in various contexts like exams, sports competitions, or organizational structures.

⚫︎ The word 第 is written with the kanji 第. ⚫︎ The reading is usually だ[第]い (dai) in hiragana. ⚫︎ There are no other ways to write the word itself. ⚫︎ No okurigana variations exist for the prefix 第.

⚫︎ 番目 (ばんめ - banme): This is a suffix that also denotes order or position, but it is placed *after* the number (e.g., 一番目 (いちばんめ - ichibanme) meaning "first"). It's more common in casual conversation. ⚫︎ 順番 (じゅんばん - junban): Order, sequence ⚫︎ 位 (くらい - kurai): Rank, position

While there isn't a direct antonym, you could consider words that indicate "last" or "end" as an opposite in the context of sequence. ⚫︎ 最後 (さいご - saigo): Last

試験で、私は[第]二位だった。 ・Translation: In the exam, I was in second place. ・Explanation: Here, 第 is used before the number "two" to indicate second place.

この本の[第]三章はとても面白い。 ・Translation: Chapter three of this book is very interesting. ・Explanation: 第 is used before "three" to refer to the third chapter.

The kanji 第 is a pictograph. 第 shows a plant growing up in the ground, and its meaning evolved to represent "first" or "beginning" and thus, subsequently, order and sequence. It does not have any further etymological roots that can be expanded on.