utrorum
utrorum is a Latin form of uter, meaning “which (of two)”. It is the genitive plural masculine adjective or genitive plural neuter adjective.
Found 26 times in the Latin texts on Socratos.
Where it is used
Caesar, De Bello Gallico 8.13.1: Non intermittunt interim cotidiana proelia in conspectu utrorumque castrorum, quae ad vada transitusque fiebant paludis.
All forms of uter (declension table)
Source: Socratos (socratos.org), a free reader for Ancient Greek and Latin. Grammar from the Perseus Treebank and Morpheus; dictionary entries from Lewis & Short, A Latin Dictionary (Perseus Digital Library, CC BY-SA). Counts are from the texts on Socratos.