LATIN DICTIONARYLexicon Latīnum
proper noun · masculinesecond declension

Rainerius

Rainerius m sg (genitive Raineriī or Rainerī)

Meaning

  1. Medieval Latinmasculinesingulara male given name from Proto-West Germanic
    Rainerius Scorcialupi notarius, scriba publicus Pisanorum […]Rainerius Scorcialupi, notary, public secretary of the Pisan […]1265 August 11, Rainerio Scorcialupi, Trattato di pace fra i pisani e l'emiro di Tunisi [Peace treaty between the Pisan and the emir of Tunis] (overall work in Old Italian); collected in Ernesto Monaci, editor, Crestomazia italiana dei primi secoli, con prospetto delle inflessioni grammaticali e glossario, volume 1, Città di Castello: S. Lapi, 1889, page 167:

Declension

declension
formsingularplural
nominativeRainerius—
genitiveRaineriī
Rainerī
—
dativeRaineriō—
accusativeRainerium—
ablativeRaineriō—
vocativeRainerī—

Origins

Derived from Proto-West Germanic *Raginahari — likely through Old Italian Rainerio — from Proto-Germanic *Raginaharjaz, derived from *raginą (“decision, advice, counsel”) + *harjaz (“commander”).

Quick answers

What does Rainerius mean in Latin?
Rainerius, a proper noun, means “a male given name from Proto-West Germanic”.
What is the genitive of Rainerius?
The genitive singular is Raineriī. Rainerius is masculine, second declension.