What does planisphaerium mean in Latin?

planisphaerium, a noun, means “planisphere”.

What is the genitive of planisphaerium?

The genitive singular is planisphaeriī. planisphaerium is neuter, second declension.

noun · neutersecond declension

planisphaerium n (genitive planisphaeriī or planisphaerī)

declension
form	singular	plural
nominative	planisphaerium	planisphaeria
genitive	planisphaeriī planisphaerī	planisphaeriōrum
dative	planisphaeriō	planisphaeriīs
accusative	planisphaerium	planisphaeria
ablative	planisphaeriō	planisphaeriīs
vocative	planisphaerium	planisphaeria

Ancient Greek σφαῖρᾰ (sphaîră)bor. Latin sphaera Latin planisphaerium From plani- + sphaera.