It is a first-class standardized Chinese character (commonly used character), which first appeared in the Warring States script, and its glyph changed from bitter (same grass) to flat tone. The original meaning of "thin" is generally considered to be overgrown with vegetation. Dense vegetation means approaching and approaching, and it also means slight, rare, contemptuous and contemptuous. "Bo" is generally used as an adjective in content words and flexibly used as a function word in The Book of Songs.

Bo was pronounced in ancient times, and there are three pronunciations in modern Chinese. Báo is mostly used in spoken language and often used alone. Bó is often used as a compound word or idiom. B only for mint. "Bo" is usually considered as a pictophonetic character. The upper part is "grass", which means that the original meaning of "thinness" is related to vegetation;

The lower part is "Pu", which means sound. Some people say that "Pu" also means meaning. "Pu" has a universal meaning. Vegetation grows very densely and becomes a "diffuse state", and the density of vegetation is written as "general". Xu Shen's Shuo Wen Jie Zi records: "Sparse, sparse forest." This means that a place with lush vegetation is called "thin". This is the original meaning of "thin".

In the Qing Dynasty, Duan Yucai's Notes on Explaining Words further vividly described the density of "thinness": "Trees can't become thinner when they push in." It can be found that the "sparse" density here has reached the point where "vegetation is intertwined and there is no gap to enter". This is extended to "no gap, close distance" and the meaning of "close, close, close" is obtained.

For example, the idiom "Sunset on the Western Hills" means that the sun is approaching the Western Hills and is about to set. Often used to indicate that people or things are close to death. The distance between the upper and lower planes of an object is very close, and there is almost no gap. "Thin" can also be extended to "the distance between the upper and lower sides of a flat object is very small". This meaning is one of the most commonly used meanings of "bo" in modern Chinese.

Fertile land is soft and deep, rich in soil organic matter and high in fertility, so it is called "thick land". On the contrary, "thin land" means that the land is not fertile. The thickness of the land indicates that the land is fertile and barren, so the meaning of "(land) is not fertile" comes from this.

It is difficult to create wealth on barren land. The meaning of the word "thin" may come from this. Poor land and poor harvest can also imply "minimal". If you change the part of speech and turn it into a verb, you can get the meaning of "contempt and neglect", for example, the idioms "favor one over the other" and "belittle yourself"

"Bo" is generally used as an adjective in real words and also as a function word in the Book of Songs, such as Xiaoya's colorful sentence: "Bo Yan's colorful sentence." "Justice" notes: "thin, words are also", that is, modifiers and auxiliary words. Nan Zhou Ge Tan: "I defile my private affairs and wash my clothes", and the word "thin" is interpreted as "nai". Bo's function words and auxiliary words are no longer used in modern Chinese.