Test oath
Black's Law Dictionary · Henry Campbell Black, M.A. · 1910
Black's Law Dictionary
An oath required to be taken as a criterion of the fitness of the person to fill a public or political office; but particularly an oath of fidelity and allegiance (past or present) to the established government. -Test-paper.
In practice
A paper or instrument shown to a jury as evidence. A term used in the Pennsylvania courts.
Depue v. Clare, 7 Pa. 428.