quadruplator
/kwɒˈdruːpleɪtə/ /kwəˈdruːpleɪtə/noun
Roman History. An informer; a person paid to denounce another in a court. Now rare.
Origin
Early 17th century; earliest use found in Robert Sanderson (1587–1663), bishop of Lincoln. From classical Latin quadruplātor public informer, person who multiplies by four from quadruplāt-, past participial stem of quadruplāre + -or.