foot-rule

Noun

footrule (plural footrules)

1. A ruler that measures in feet.
   • To argue as if there were somewhere a concrete thing called justice — like a footrule — is an illusion. A footrule that was six inches long at one time and twelve at another, would create inextricable confusion, its length being altered and not its name […]1873, Henry Bleckly, A Colloquy on the Utilitarian Theory of Morals Presented in Mr. W. E. H. Lecky's History of European morals from Augustus to Charlemagne