"Waving" is not an idiom, but a common compound word, which is similar to shaking your head, twisting your waist, shaking hands, drinking water, bathing, opening your mouth, running, dancing, writing, singing, helping, changing clothes, combing your hair, washing your face and washing your hair.

According to the characteristics of morphemes, compound words are divided into derivative words and compound words. The meaning of derivative words comes from the meaning of root morphemes, such as "grandma, reader, stone" and so on. Compound words are completely composed of several root morphemes according to certain rules, and their meanings are composed of the meanings of two morphemes, such as "Beauty, Daoxiang and Shanchuan".

Extended data:

The semantic structure of compound words is essentially a cognitive field, which can be attributed to a certain cognitive framework. Compound words are the mapping of the components of a frame (including simple frame and compound frame) on the language surface.

Every word that constitutes a compound adjective should be connected by a hyphen to avoid confusion and ambiguity. Adjectives composed of hyphens can simply explain a complex concept with one word, which is concise.