Where does “ギニアビサウ共和国” come from?

ギニアビサウ共和国 (Japanese) comes from Japanese ギニアビサウ, from English Guinea-Bissau, from English Guinea, from Portuguese Guiné, from English -ia, from Latin -ia, from Latin -ius, from Proto-Italic -jōs — Creates adjectives from noun or verb stems.

Ancestry of “ギニアビサウ共和国”, step by step

ギニアビサウ共和国 traces back through two separate lines of ancestry.

via Japanese ギニアビサウ

StepLanguageWordMeaning
1JapaneseギニアビサウGuinea-Bissau
2EnglishGuinea-Bissau
3EnglishGuineaA gold coin originally worth twenty shillings; later (from 1717 until the adoption of decimal currency) standardised at a value of twenty-one shillings
4PortugueseGuinéGuinea
5English-iaUsed in forming names of countries, diseases,...
6Latin-iaUsed to form a feminine abstract noun, usually...
7Latin-iusforming adjectives from nouns; nominative neuter...
8Proto-Italic-jōsForms comparative adjectives
9Proto-Indo-European-yósCreates adjectives from noun or verb stems

via Japanese 共和国

StepLanguageWordMeaning
1Japanese共和国republic
2Japanesea land, a large place; a country in general, a...
3Old Japanese
Every word from Proto-Indo-European -yósEvery word from Latin -iaEvery word from Latin -ius