Simple Definition of vacuous
: having or showing a lack of intelligence or serious thought : lacking meaning, importance, or substance
Examples of vacuous in a sentence
a dull and vacuous movie
He had a vacuous expression on his face.
Did You Know?
As you might have guessed, "vacuous" shares the same root as "vacuum"-the Latin adjective vacuus, meaning "empty." This root also gave us the noun "vacuity" (the oldest meaning of which is "an empty space") as well as the verb "evacuate" (originally meaning "to empty of contents"). Its predecessor, the verb "vacare," is also an ancestor of the words "vacation" and "vacancy" as well as "void." All of these words suggest an emptiness of space, or else a fleeing of people or things from one place to another. "Vacuous" appeared in English in the middle of the 17th century, at first literally describing something that was empty. It acquired its figurative usage, describing one who is lacking any substance of the mind, in the mid-1800s.
Origin of vacuous
First Known Use: circa 1660
Synonym Discussion of vacuous
Seen and Heard
What made you want to look up vacuous? Please tell us where you read or heard it (including the quote, if possible).