What does Praenestīnus mean in Latin?

Praenestīnus, a noun, means “Praenestine”.

What is the genitive of Praenestīnus?

The genitive singular is Praenestīnī. Praenestīnus is masculine, second declension.

noun · masculinesecond declension

Praenestīnus m sg (genitive Praenestīnī)

Proto-Indo-European *-nós Proto-Indo-European *-iHnos Proto-Italic *-īnos Latin -īnus Latin Praenestīnus From Praeneste + -īnus.

Descendants

adjectivefirst/second-declension adjective

Praenestīnus²

Praenestīnus (feminine Praenestīna, neuter Praenestīnum)

singular
form	masculine	feminine	neuter
nominative	Praenestīnus	Praenestīna	Praenestīnum
genitive	Praenestīnī	Praenestīnae	Praenestīnī
dative	Praenestīnō	Praenestīnae	Praenestīnō
accusative	Praenestīnum	Praenestīnam	Praenestīnum
ablative	Praenestīnō	Praenestīnā	Praenestīnō
vocative	Praenestīne	Praenestīna	Praenestīnum

plural
form	masculine	feminine	neuter
nominative	Praenestīnī	Praenestīnae	Praenestīna
genitive	Praenestīnōrum	Praenestīnārum	Praenestīnōrum
dative	Praenestīnīs	Praenestīnīs	Praenestīnīs
accusative	Praenestīnōs	Praenestīnās	Praenestīna
ablative	Praenestīnīs	Praenestīnīs	Praenestīnīs
vocative	Praenestīnī	Praenestīnae	Praenestīna

Proto-Indo-European *-nós Proto-Indo-European *-iHnos Proto-Italic *-īnos Latin -īnus Latin Praenestīnus From Praeneste + -īnus.