vaporousEnglishOxford New American Dictionaryvaporous /ˈvāp(ə)rəs, ˈveɪp(ə)rəs / ▸ adjective 1 of the nature of, characterized by, or filled with vapor: the vaporous atmosphere vaporous poisons. 2 lacking in substance or clarity; vague: the vaporous notion of free will the terminology is rather vaporous. – DERIVATIVES vaporousness