Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
quīnĭo, ōnis, m. [quini], the number five, a pentad (post-class.): quinionem filiorum eniti, Tert. Anim. 6: voluminum, id. ib. 46.
Esp. at dice, a five, a cinque, Isid. Orig. 18, 65.