monstri
monstri is a Latin form of monstrum, meaning “portent, omen; monster”. It is the genitive singular neuter noun.
Found 60 times in the Latin texts on Socratos.
Where it is used
Cicero, In C. Verrem 2.2.158: … a fuerunt: ecquo de homine hoc umquam audivistis? novum est, iudices, in Siculis quidem et in omnibus Graecis monstri simile. non crederem hoc de statuis nisi iacentis revulsasque vidissem, propterea quod apud omnis Graecos hic …
Ovid, Metamorphoses 12.175: femina natus erat.” Monstri novitate feruntur
All forms of monstrum (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.