VACUOUS Meaning of VACUOUS in English adj. 1 lacking expression (a vacuous stare). 2 unintelligent (a vacuous remark). 3 empty. vacuity n. vacuously adv. vacuousness n.[ L vacuus empty (as VACATE) ] Concise Oxford English dictionary. Краткий оксфордский словарь английского языка. 2012