rationis

rationis is a Latin form of ratio, meaning “reason, account; method; plan”. It is the genitive singular feminine noun.

Found 181 times in the Latin texts on Socratos.

Where it is used

Cicero, In C. Verrem 2.2.70: … s e conventu Syracusano, qui Sacerdoti quoque in consilio fuerant tum cum est idem hic Sopater absolutus. hoc rationis habebant, facere eos nullo modo posse ut eodem crimine eisdem testibus Sopatrum condemnarent idem homines qui …

Pliny the Younger, Epistulae 10.99.1: Rationis est, mi Secunde carissime, contegi aquam istam, quae per civitatem Amastrianorum fluit, si intecta salubritati obest. Pecunia ne huic operi desit, curaturum te secundum diligentiam tuam certum habeo.

All forms of ratio (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.