Vacuous is an adjective that means empty or lacking content.
Coming from the Latin word vacuus (vah KOOS) meaning ‘empty’ our word of the day shares its roots with words like vacuum, evacuate and vacant. It often refers to ideas or thoughts that are empty in a metaphorical sense, meaning they have no intelligent content behind them.
I was disappointed by professor Harold’s lecture. It contained mostly vacuous catchphrases but very few actual ideas.