'assonance' originates from Latin, specifically the verb 'assonare' (formed from the prefix 'ad-' + 'sonare'), where 'ad-' meant 'to/toward' and 'sonare' meant 'to sound'.

'assonance' passed into English via Old French (e.g. 'assoner'/'assonance') and Middle English, eventually becoming the modern English noun 'assonance' and adjectival/verb forms such as 'assonant' and rare verbal uses.

Initially, the root sense was simply 'to sound to' or 'to make sound together'; over time it narrowed to the modern sense of 'correspondence or repetition of vowel sounds' (the poetic device 'assonance').