What is the term for the creation of new words and expressions?

The term for the creation of new words and expressions is neologism. Neologisms arise when new concepts, inventions, or cultural phenomena emerge, necessitating the development of a unique term to describe them. This process reflects the dynamic nature of language, which evolves to meet the communicative needs of society.

Neologisms can come from various sources, including technological advancements, social changes, or even artistic movements. They play a crucial role in keeping language current and relevant. For instance, terms like "selfie" or "blog" were created as culture shifted with the advent of new technologies.

In contrast, paraphrasing involves rewording existing text or speech, synonymization refers to using synonyms in place of original words, and metaphorization entails using metaphors to create imagery or convey ideas, which do not align with the idea of creating entirely new words or expressions.