What literary device is the repetition of initial sounds in neighboring words?

The literary device that repeats initial sounds in neighboring words is alliteration.

Alliteration usually repeats consonant sounds at the beginnings of nearby stressed syllables, as in “Peter Piper picked a peck of pickled peppers.” It is sound-based, so matching letters are not required: “chemical chaos” alliterates even though the letters differ in pronunciation.

The term comes from Latin littera, meaning “letter.” Italian humanist Giovanni Pontano coined it in the 15th century, although he used it more broadly than modern literary terminology. Alliteration was especially important in Old English verse, including Beowulf, where repeated initial sounds helped organize poetic lines and support memorization.

A common mix-up is consonance, which repeats consonant sounds anywhere in words, not necessarily at the beginning. Assonance repeats vowel sounds, while rhyme generally concerns matching sounds at the ends of words. Alliteration remains common in headlines, advertising, song lyrics, names, and tongue twisters because it creates rhythm and makes phrases memorable.