What does antarcticus mean in Latin?

antarcticus, a adjective, means “southern; Antarctic (in taxonomic names)”.

How do you pronounce antarcticus?

In classical Latin, [anˈtark.tɪ.kʊs]; in ecclesiastical (church) Latin, [anˈtark.ti.kus].

adjectivefirst/second-declension adjective

antarcticus (feminine antarctica, neuter antarcticum)

Classical[anˈtark.tɪ.kʊs]Ecclesiastical[anˈtark.ti.kus]

singular
form	masculine	feminine	neuter
nominative	antarcticus	antarctica	antarcticum
genitive	antarcticī	antarcticae	antarcticī
dative	antarcticō	antarcticae	antarcticō
accusative	antarcticum	antarcticam	antarcticum
ablative	antarcticō	antarcticā	antarcticō
vocative	antarctice	antarctica	antarcticum

plural
form	masculine	feminine	neuter
nominative	antarcticī	antarcticae	antarctica
genitive	antarcticōrum	antarcticārum	antarcticōrum
dative	antarcticīs	antarcticīs	antarcticīs
accusative	antarcticōs	antarcticās	antarctica
ablative	antarcticīs	antarcticīs	antarcticīs
vocative	antarcticī	antarcticae	antarctica

antarctĭcus, a, um, adj., = ἀνταρκτικός,

I. southern, Hyg. Astr. 1, 6; App. de Mundo, p. 57 (in Varr. L. L. 9, § 24 Müll., written as a Greek word).

Borrowed from Ancient Greek ἀνταρκτικός (antarktikós, “opposite the Arctic”).