What does Ulla mean in Latin?

Ulla, a proper noun, means “A river of Gallaecia, Hispania Tarraconensis, still called this way”.

What is the genitive of Ulla?

The genitive singular is Ullae. Ulla is masculine, first declension.

proper noun · masculinefirst declension

Ulla m sg (genitive Ullae)

masculinesingularA river of Gallaecia, Hispania Tarraconensis, still called this way

From Paleo-Hispanic, ultimately from Proto-Indo-European *u̥lH-yeh₂, from the zero-grade of Proto-Indo-European *welH- (“to turn, wind”).

What does Ulla mean in Latin?: Ulla, a proper noun, means “A river of Gallaecia, Hispania Tarraconensis, still called this way”.
What is the genitive of Ulla?: The genitive singular is Ullae. Ulla is masculine, first declension.