Urim and Thummim /ˈjəɹ.əm ænd ˌθəm.məm/ noun[plural only]2 •Certain sacred objects (whose precise form and nature is unknown) that were worn on the breastplate of the Jewish high priest, as described in the Bible, and used in divination or casting lots.Should Kings and Nations from thy mouth consult, / Thy Counsel would be as the Oracle / Urim and Thummim, those oraculous gems / On Aaron’s breast: or tongue of Seers old / Infallible; […] — 1671 •Instruments by which divine revelation can be understood; often specifically the tools that Joseph Smith, Jr. said he had found on the hill Cumorah and used to interpret the golden plates.
