silly as a wheel
(as) silly as a wheel
Particularly foolish, silly, or frivolous. Primarily heard in Australia. Everyone thought I was silly as a wheel growing up—my head in the clouds, lost to dreams of impossible things. The government's proposed scheme to fix income inequality by overhauling the tax code in favor of corporations is about as silly as a wheel.
silly as a wheelvery silly. Australian
1985 John Clanchy The Lie of the Land Father Tierney was mad. Cracked as an egg, some boys said, silly as a wheel.