自

It signifies "self" or "one’s own.

The character 自 originally was a pictogram representing the human nose and is the root form of 鼻 (nose). However, before there was a specific character meaning "oneself" or "self," 自 was borrowed to mean "nose." Over time, the meaning of "nose" was lost for 自, and a new derivative character 鼻 was created specifically for "nose." This semantic shift happened long ago and became fixed, making 自 a classic example of a phonetic loan character (假借, jia jie).

Culturally and linguistically, in Chinese and Japanese traditions, the nose is often used to refer to oneself, which likely contributed to 自 acquiring the meaning of "self" or "oneself."

Additionally, in Classical Chinese, 自 also functions as a preposition meaning "from" or "since." For example, the phrase 自古 (since ancient times) uses this character, as does the construction 自A至B meaning "from A to B."

When used as a radical, it generally conveys meanings related to the nose, sense of smell, or breathing.

It is usually placed at the top part of a character, forming a vertical (top-bottom) structure.