Fatuous means silly and self-satisfied. A fatuous remark, a fatuous grin, fatuous nonsense.
The self-satisfaction is what makes it sting, since a fatuous remark is stupid and pleased with itself at once. It is a different word from famous and from fatal despite the look of it.
1adjectivefatuousSilly and self-satisfied.
“He made a fatuous comment about the weather, then laughed loudly at his own joke.”
fatuous is a quality.
Latin fatuus means foolish or simple, and is also the source of infatuated, which first meant made foolish.
Latin
fatuus — foolish, silly, simple
English, today
fatuous
From Latin fatuus (“foolish, silly, simple”).
Etymology from Wiktionary, CC BY-SA