What does Olgerdus mean in Latin?

Olgerdus, a proper noun, means “a male given name from Lithuanian”.

What is the genitive of Olgerdus?

The genitive singular is Olgerdī. Olgerdus is masculine, second declension.

In classical Latin, [ɔɫˈɡɛr.dʊs]; in ecclesiastical (church) Latin, [ol̠ʲˈd͡ʒɛr.dus].

proper noun · masculinesecond declension

Olgerdus m sg (genitive Olgerdī)

Classical[ɔɫˈɡɛr.dʊs]Ecclesiastical[ol̠ʲˈd͡ʒɛr.dus]

Medieval LatinNew Latinmasculinesingulara male given name from Lithuanian
Et inter omnes filios placuit duci Olgerdo dux Jagello, duci autem Kyerstuchi placuit dux Vitoldus.And among all the sons, Duke Jogaila was pleasing to Duke Algirdas, while Duke Vytautas was pleasing to Duke Kęstutis.c. 15th century, Origo regis Jagyelo et Wytholdi ducum Lithuanie:

A Latinization of Old Ruthenian Ольгѣрдъ (Olʹhěrd), from Lithuanian Algirdas.