What does leucogaster mean in Latin?

leucogaster, a noun, means “white belly”.

What is the genitive of leucogaster?

The genitive singular is leucogasteris. leucogaster is feminine, variously declined, third declension, second declension.

noun · femininevariously declined, third declension, second declension

leucogaster f (genitive leucogasteris or leucogastrī)

declension
form	singular	plural
nominative	leucogaster	leucogasterēs leucogastrī
genitive	leucogasteris leucogastrī	leucogasterum leucogastrōrum
dative	leucogasterī leucogastrō	leucogasteribus leucogastrīs
accusative	leucogasterem leucogastrum	leucogasterēs leucogastrōs
ablative	leucogastere leucogastrō	leucogasteribus leucogastrīs
vocative	leucogaster	leucogasterēs leucogastrī

From Ancient Greek λευκός (leukós, “white”) + gaster (“belly”).