1. Word choice: This directly highlights the aspect of diction focused on selecting specific words.
2. Language: This is a broader term encompassing all aspects of language use, including vocabulary, grammar, and syntax.
3. Vocabulary: This focuses on the specific words used by a speaker or writer, emphasizing the breadth and depth of their word knowledge.
The most appropriate synonym for "diction" will depend on the context and the specific nuance you want to convey.