Erya is a literary work of lexicography, which was first included in the History of Han Dynasty, but the author's name was not included. Rich ancient Chinese vocabulary is collected in the works. It is not only the ancestor of dictionaries, but also an ancient book-Jing, which is included in the Thirteen Classics. It is the core component of the traditional culture of the Han nationality.
Erya is the first dictionary. Er means near (later written as near), and Ya means right. This refers to Yayan, a language with standard pronunciation, vocabulary and grammar. Erya means to be close to elegance and conform to elegance, that is, to interpret ancient Chinese words and dialect words in an elegant way to make them close to norms.
Er Ya was written between the Warring States Period or the Han Dynasty, and the upper limit should not be earlier than that of the Warring States Period, because some materials used in the book came from books such as Chu Ci, Zhuangzi and Lv Chunqiu, all of which were works after the Warring States Period. Some animals mentioned in the book, such as lynx (suān ní, one of the nine sons of the dragon, shaped like a lion).
According to textual research, it has not been seen before in the Warring States period. Some people think that the writing limit of Er Ya will not be later than that of the Western Han Dynasty, because Dr Er Ya was already set up in Emperor Wen of Han Dynasty, and Er Ya Zhu, which was regarded as literature, appeared in Emperor Wu of Han Dynasty.