It was first seen in Chu Bamboo Books in the Warring States Period? Its original meaning is to express what you think, and later it is extended to mean that things are wonderful and full of life interest or can trigger strong feelings. Shuowen Jiezi is considered as "the expression of the mind".
Extended data:
In terms of glyphs, according to Zhou Zongce's research, the word "poem" developed from the basic symbols shown.
Symbol first develops into symbol, and then develops into symbol (temple), which refers to the significance of a specific behavior accompanied by some actions, music, songs and dances in sacrifice. Later, when music, songs, poems and words were emphasized, the word "expression" came into being and eventually evolved into the word "poem".
From the semantic point of view, the word "poem" is closely related to the word "ambition": thoughts and feelings are the "ambition" in "heart" and the word "poem" in "speech"-that is, the original meaning of the word "poem" is the language to express the thoughts in the heart. After the Han dynasty, the form and meaning of the word "poem" have been relatively stable and have not changed much.
References:
Baidu encyclopedia-poetry