E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
A barbarous word from the Latin prmoneri (to be forewarned). The words of the writ begin Prmunire facias A.B.i.e. Cause A. B. to be forewarned, to appear before us to answer the contempt wherewith he stands charged. If A. B. refuses to do so, he loses all civil rights, and before the reign of Elizabeth might have been slain by anyone with impunity.