1727, "resemblance of sounds between words," from French assonance, from assonant, from Latin assonantem (nominative assonans), present participle of assonare "to resound, respond to," from ad- "to" (see ad-) + sonare "to sound" (see sonata). Properly, in prosody, "rhyming of accented vowels, but not consonants" (1823).