Meaning
A very remote, godforsaken place; the middle of nowhere.
Example
Ele foi morar num sítio no cafundó do Judas, a três horas da cidade mais próxima.
He went to live on a small farm out in the middle of nowhere, three hours from the nearest town.
Origin
The expression has two parts. The noun cafundó means a deep, remote, hard-to-reach spot; major dictionaries mark its etymology cautiously as "possibly of African origin," and it is popularly tied to Kimbundu, a Bantu language of Angola — the same root behind the real Cafundó quilombo in São Paulo state, a community descended from enslaved Africans.
Sources: Priberam, CNN Brasil.
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