/ ˈvɔːntɪd; NAmE / adjective
[ usually before noun ] ( formal ) proudly talked about or praised as being very good, especially when this is not deserved :
Their much vaunted reforms did not materialize.
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WORD ORIGIN
late Middle English : the noun a shortening of obsolete avaunt boasting, a boast ; the verb (originally in the sense use boastful language ) from Old French vanter , from late Latin vantare , based on Latin vanus vain, empty + -ed .