Locution refers to the act or manner of speaking or writing, including the choice of words and their arrangement.
Here are some other words that might fit depending on the context:
* Language - a system of communication used by a particular country or community.
* Speech - the ability to talk, the act of speaking.
* Discourse - written or spoken communication or debate.
* Expression - the process of making known one's thoughts or feelings.
* Verbalization - the act of expressing something in words.