From Longman Dictionary of Contemporary Englishassonanceas‧so‧nance /ˈæsənəns/ noun [uncountable] technical SLsimilarity in the vowel sounds of words that are close together in a poem, for example between ‘born’ and ‘warm’
Examples from the Corpus
assonance• There is a recurrence of the e-a assonance at the ends of lines, but in no definable pattern.• Are there any phonological patterns of rhyme, alliteration, assonance, etc?• The photographs are linked across the book by fleeting resemblances, oppositions, repetitions, the pictorial equivalents of assonance and half-rhyme.Origin assonance (1700-1800) French Latin assonare “to answer with the same sound”, from ad- “to” + sonare “to sound” 