alliteration

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. The repetition of the same sounds or of the same kinds of sounds at the beginning of words or in stressed syllables, as in "on scrolls of silver snowy sentences” ( Hart Crane). Modern alliteration is predominantly consonantal; certain literary traditions, such as Old English verse, also alliterate using vowel sounds.

Century Dictionary and Cyclopedia

1. n. The repetition of the same letter or sound at the beginning of two or more words in close or immediate succession; the recurrence of the same initial sound in the first accented syllables of words; initial rime: as, many men, many minds.
2. n. Alliteration was a characteristic of old Teutonic poetry (Anglo-Saxon and Middle English, Old Saxon, Icelandic, etc.), terminal rime, as a regular feature, being of later (Romance) introduction. The lines were divided into two sections, the first having regularly two alliterating syllables, the second one; but by license or mere accident four or more alliterating syllables might occur, as in the last line of the extract from Piers Plowman. The alliterating syllable was always accented, and was not necessarily initial, as written; it might follow an unaccented prefix, as ar-raye in the extract. The vowels, being all more or less open and easy of utterance, might alliterate with one another. In Churchill's line “Apt alliteration's artful aid,” given above, the initial vowel-sounds are different (a, a or a, ȧ, ā), though spelled with the same letter. The following is an example of Middle English alliteration:
3. n. Chaucer's verse is cast on the Romance model with final rime, but he often uses alliteration as an additional ornament:
4. n. Such alliteration is much affected by Spenser and his imitators, and occurs with more or less frequency in all modern poetry.

Wiktionary

1. n. The repetition of consonants at the beginning of two or more words immediately succeeding each other, or at short intervals.
2. n. The recurrence of the same letter in accented parts of words, as in Anglo-Saxon alliterative meter.

GNU Webster's 1913

1. n. The repetition of the same letter at the beginning of two or more words immediately succeeding each other, or at short intervals; as in the following lines:

WordNet 3.0

1. n. use of the same consonant at the beginning of each stressed syllable in a line of verse