Urim and Thummim

Meanings

1. 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.
2. 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.

Etymology

From Biblical Hebrew אוּרִים (ʾûrîm) and תומים / תֻּמִּים (tummîm). Traditionally the Hebrew has been understood, and sometimes translated, as “Light and Truth” owing to the similarity to אוֹרִים (ʾôrîm, “lights”) and תָּמִים (tāmîm, “complete, morally upright, in accordance with truth”), an interpretation that has contributed to the terms’ association with clairvoyance. There is no consensus on the validity of this reading in the original biblical context, particularly for Thummim.