ad valorem Syllabification: (ad va·lo·rem)Pronunciation: /ˌad vəˈlôrəm/Definition of ad valorem adverb & adjective (of the levying of tax or customs duties) in proportion to the estimated value of the goods or transaction concerned. Origin: late 17th century: Latin, literally 'according to the value'ad valorem in other Oxford dictionaries Definition of ad valorem in the British & World English dictionary
