What does nipponicus mean in Latin?

nipponicus, a adjective, means “Japanese, Nipponese”.

How do you pronounce nipponicus?

In classical Latin, [nɪpˈpɔ.nɪ.kʊs]; in ecclesiastical (church) Latin, [nipˈpɔː.ni.kus].

adjectivefirst/second-declension adjective

nipponicus (feminine nipponica, neuter nipponicum)

Classical[nɪpˈpɔ.nɪ.kʊs]Ecclesiastical[nipˈpɔː.ni.kus]

singular
form	masculine	feminine	neuter
nominative	nipponicus	nipponica	nipponicum
genitive	nipponicī	nipponicae	nipponicī
dative	nipponicō	nipponicae	nipponicō
accusative	nipponicum	nipponicam	nipponicum
ablative	nipponicō	nipponicā	nipponicō
vocative	nipponice	nipponica	nipponicum

plural
form	masculine	feminine	neuter
nominative	nipponicī	nipponicae	nipponica
genitive	nipponicōrum	nipponicārum	nipponicōrum
dative	nipponicīs	nipponicīs	nipponicīs
accusative	nipponicōs	nipponicās	nipponica
ablative	nipponicīs	nipponicīs	nipponicīs
vocative	nipponicī	nipponicae	nipponica

Likely derived from Japanese 日本 (Nippon, “Japan”) + -icus.