Diction (Latin: dictionem (nom. dictio), "a saying, expression, word") refers to the way a writer or speaker chooses words and expresses ideas in a piece of writing, such as a poem or story. In a more common sense, diction describes how clearly someone speaks so that each word is heard and understood fully. This involves pronunciation and tone, not the choice of words or style. This is often called enunciation or articulation.

Diction includes several aspects, with register being the most important. Register refers to how speech or writing changes in formality based on the situation or audience. When analyzing literary diction, writers can see how tone and character traits are shown. For example, using many verbs that describe movement may suggest an active character, while using many verbs that describe thoughts may show an introspective character. Diction also affects how words are chosen and how sentences are structured.

Aristotle, in The Poetics (20), lists parts of diction (λέξις) as the letter, syllable, conjunction, article, noun, verb, case, and speech (λόγος). However, one commentator notes that the text is unclear, and some words have many meanings, making it difficult to know exactly what Aristotle intended.

In literature

Diction refers to the choice of words and phrases used in writing or speaking. It is often judged based on common standards of proper language and is considered a sign of good quality in writing. Diction can also be unique to a writer or character, as certain words or phrases may be used repeatedly by them.

Some modern writers use old-fashioned words like "thy," "thee," and "wherefore" to give their work a style similar to that of Shakespeare.

There are different types of diction: archaic diction uses very old words that are rarely used today, high diction uses formal and grand-sounding language, and low diction uses simple, everyday language. Each type helps an author express ideas or create artistic effects in their writing.