Histrum

Histrum is a Latin form of Istrus, meaning “Istrian; (Hister) the Danube”. It is the genitive plural neuter adjective or genitive plural masculine adjective or accusative singular masculine adjective or nominative singular neuter adjective.

Found 28 times in the Latin texts on Socratos.

Where it is used

Ovid, Tristia 3.12.29: nec mare concrescit glacie, nec, ut ante, per Histrum

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.