the effect created when two syllables in words that are close together have the same vowel sound, but different consonants, or the same consonants but different vowels, for example, sonnet and porridge or cold and killedsee alsoalliterationSee related entries:Linguistic devicesWord Originearly 18th cent.: from French, from Latin assonare ‘respond to’, from ad- ‘to’ + sonare (from sonus ‘sound’).
See assonance in the Oxford Advanced American Dictionary