1643. Prynne, Sov. Power Parl., II. 59 b. This their ancient undubitable oft-enjoyed Right and Priviledge.
1664. H. More, Myst. Iniq., 207. A sense of things … so coherent with undubitable Principles.
1816. Bentham, Chrestom., 208. To judge from the undubitable etymologies of the two words.
