Urim and Thummim means in the bible: Hebrew word that refers to “Lights and Perfections”. An instrument made by God for man’s benefit in receiving revelation from God and translating languages. Ex. 28:30; Lev. 8:8; Num. 27:21; Deut. 33:8; 1 Sam. 28:6; Ezra 2:63; Neh. 7:65; JS–H 1:35.
(in Bible Dictionary)