What does Schirgalō mean in Latin?

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

What is the genitive of Schirgalō?

The genitive singular is Schirgalōnis. Schirgalō is masculine, third declension.

In classical Latin, [ˈskʰɪr.ɡa.ɫoː]; in ecclesiastical (church) Latin, [ˈskir.ɡa.lo].

proper noun · masculinethird declension

Schirgalō m sg (genitive Schirgalōnis)

Classical[ˈskʰɪr.ɡa.ɫoː]Ecclesiastical[ˈskir.ɡa.lo]

Medieval LatinNew Latina male given name from Lithuanian
Nos Schirgalo dei gracia dux lithuanie et dominus Tracensis et Polocensis etc. universis ad quos presens littera devoluta fuerit publice recognoscimus et profitemur Quod conveucionem in insula iuxta fluvium Dobise cum honorabilibus et Religiosis dominis Magno commendatore supremo marschalco et Thesaurario ordinis beate Marie virgiuis Theuton.We, Skirgaila, by the grace of God, Duke of Lithuania and Lord of Trakai and Polotsk, etc., publicly recognize and profess to all to whom the preset letter shall be brought, that [we have made] an agreement on the island near the river Dubysa with the honorable and religious lords, the Grand Commander, the Supreme Marshal, and the Treasurer of the Order of the Blessed Virgin Mary of the Teutons.1253–1433, Codex Diplomaticus Lithuaniæ, II, IX, page 48:

A Latinization of Old Ruthenian Скирге́ла (Skirhéla), from Lithuanian Skirgaila.