Frank J. Wilstach, comp. A Dictionary of Similes. 1916.
Stupid
Stupid as an excuse.
—Anonymous
Stupid as a sloth.
—Anonymous
Stupid as a fact.
—Honoré de Balzac
Stupid as a stone.
—Robert Browning
Loftily stupid, like dumb idols.
—Thomas Carlyle
Stupid as a coot.
—Frank Cowan (Dictionary of Sea Proverbs)
Stupid as a little downy owl.
—George Du Maurier
Stupid … like Falstaff in his old age.
—Thomas H. Huxley
Stupid as a log.
—Isaac Jackman
Stupid as hounds chasing an iron deer.
—Sydney Munden
Stupid as a post.
—Clement Robinson
Stupid as the swine.
—Hans Sachs
Stupid as a hog.
—Leo Tolstoy