▪ a defect in a crystal lattice, consisting of the absence of an atom or an ion from a position where there should be one.
3. lack of intelligence or understanding:"vacancy, vanity, and inane deception"Similarempty-headednesslack of thoughtlack of intelligencebrainlessnessdensenessthicknessvacuousnessvacuityinanenessinanitystupidityOppositeintelligence