isset
isset is a Latin form of eo, meaning “go, walk”. It is the 3rd person singular pluperfect active subjunctive.
Found 41 times in the Latin texts on Socratos.
Where it is used
Cicero, Pro S. Roscio Amerino 64: … am Terracinensem, hominem non obscurum, cum cenatus cubitum in idem conclave cum duobus adulescentibus filiis isset, inventum esse mane iugulatum. cum neque servus quisquam reperiretur neque liber ad quem ea suspicio pertiner …
Ovid, Heroides 12.15: Isset anhelatos non praemedicatus in ignes
All forms of eo (conjugation 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.