common person; foolish commoner; mediocrity
A somewhat literary or formal term for an ordinary, unenlightened person, often with a nuance of foolishness or lack of refinement. Can be used self-deprecatingly or to describe the masses.
As a mere commoner, I could not grasp that profound thought.
He called himself a foolish commoner and never acted superior.
Compound of 凡 (bon, 'ordinary, mediocre') and 愚 (gu, 'foolish'). The exact historical derivation is uncertain, but the combination straightforwardly yields the meaning 'foolish commoner'.