vac·u·ous 
/ˈvækjəwəs/ adjective
/ˈvækjəwəs/ adjective [more vacuous; most vacuous] formal : having or showing a lack of intelligence or serious thought : lacking meaning, importance, or substance
▪ a dull and vacuous movie ▪ vacuous comments/remarks ▪ He had a vacuous expression on his face.
▪ a dull and vacuous movie ▪ vacuous comments/remarks ▪ He had a vacuous expression on his face.
— vac·u·ous·ly adverb
▪ He smiled vacuously for the camera.
▪ He smiled vacuously for the camera.
— vac·u·ous·ness noun [noncount]
