一

表示数字“1”，是自然数中最小的正整数。此外，它还可以表示某个、一旦、全部、相同、一样等多种含义。

Indicates the numeral "1", the smallest positive integer among natural numbers. Additionally, it can signify "a/an/one", "once/as soon as", "whole/all", "same", "alike", and other meanings.

“一”作为数词，最基本的功能是表示数量上的“一个”或“第一”。在句中常修饰名词或量词。它也可以用作副词，表示“一旦”、“一…就…”（表示动作的紧接着发生），或者强调某个小的量。还可以表示“相同”、“一样”或“全部”。在特定语境下，它还能用于构成四字词语或成语，表达更丰富的意义。

"一" (yī) primarily functions as a numeral, most fundamentally indicating "one" in quantity or "first". In sentences, it often modifies nouns or measure words. It can also be used as an adverb to mean "once", "as soon as...then..." (indicating immediate sequence of actions), or to emphasize a small quantity. Furthermore, it can express "same", "alike", or "entirety". In specific contexts, it can also form four-character idioms or chengyu, conveying richer meanings.