Etymology tree
Old Tupi kariîó
Proto-Tupian *ekʷ
Proto-Tupi-Guarani *ok
Proto-Tupian *-ap
Proto-Tupi-Guarani *-aβ?
Old Tupi -a
Old Tupi oka
Old Tupi Kariîookabor.
Portuguese carioca
From Old Tupi Kariîooka, a former indigenous village in what is now Guanabara Bay.