General synonyms:
* Diction
* Lexical choice
* Vocabulary
* Phraseology
* Language
* Expression
* Style
* Verbiage
More specific synonyms depending on the context:
* Formal/Informal: For example, you might say "register" or "tone" if you're discussing the formality of language.
* Figurative Language: You might say "imagery" or "metaphor" if you're discussing the use of figurative language.
* Connotation: You might say "nuance" or "implication" if you're discussing the subtle meanings conveyed by word choice.
The best synonym will depend on the specific context in which you are using the term "word choice".