The journey of 'vaunt' is a story of emptiness giving rise to boastful sound. Its ultimate source is the Latin adjective 'vānus', which carried the core meaning of "empty, void, or lacking substance". From this, the Late Latin verb 'vānitāre' was formed, literally meaning "to make empty" but semantically shifting to describe the act of making empty or idle claims—that is, to boast. This term passed into Old French and Anglo-French as 'vanter', retaining the sense of proud, often excessive, self-praise. When English adopted it in the late Middle Ages, the spelling settled as 'vaunt', capturing both the action of bragging and the boast itself, a meaning that persists today, linking hollow vanity to loud self-aggrandizement.

The word 'vaunt' is a simplex form. It entered English from the Anglo-French verb 'vanter', meaning "to praise, to boast". This, in turn, derives from the Late Latin 'vānitāre', a verb meaning "to talk emptily, to boast", which is based on the Latin root 'vānus', meaning "empty, idle, vain".