Leviticus 8:8

וַיָּשֶׂם עָלָיו אֶת הַחֹשֶׁן וַיִּתֵּן אֶל הַחֹשֶׁן אֶת הָאוּרִים וְאֶת הַתֻּמִּים

He placed the breastplate upon him; and in the breastplate he put the Urim and the Tumim.

Most of the garments of the kohein gadol (high priest) translate fairly easily. For example, “choshen” in Hebrew is “breastplate” in English. But what are these Urim and Tumim? We know from elsewhere in the Bible that the kohein gadol consulted them for Divine guidance on matters of national import but the meaning of the name is obscure. Accordingly, just as we have done, Onkelos leaves the words untranslated, albeit in their Aramaic form, uraya and tumaya.