If someone smiles at you in a way that seems fake or empty, you could describe the smile as vacuous. An example of a vacuous comment would be a politician promising to make things better without explaining how. If something is vacuous, it's like a vacuum — hollow, empty, devoid of substance.

What is meant by vacuous?

1 : emptied of or lacking content. 2 : marked by lack of ideas or intelligence : stupid, inane a vacuous mind a vacuous movie.

What is a vacuous person?

The definition of vacuous is empty or not intelligent. An example of vacuous is a ditzy person who has no smart or useful ideas. adjective.