Diction is the choice of words a writer or speaker uses. When your teacher talks about improving your diction in an essay, she means picking words that express your ideas more clearly or powerfully. Should you write “big” or “enormous”? “Said” or “whispered”? Those choices are your diction.

The word also refers to how clearly someone pronounces words when speaking. An actor with good diction speaks so that every word can be understood, even from the back of the theater. A mumbler has poor diction because their words blur together.

Writers develop their diction to match their purpose. A scientist uses precise, technical diction in a research paper. A poet might choose musical, surprising words. A news reporter aims for clear, straightforward diction that everyone can understand. Even in conversation, you probably adjust your diction: you might say “Yeah, totally!” to a friend but “Yes, I agree” when talking to your principal.

Good diction means choosing words that say exactly what you mean and suit the situation. It's not about using the fanciest words you know. It's about using the right words, the ones that make your meaning unmistakable and your voice sound authentic.