The word "goundou" may seem tricky to spell, but it follows a consistent pattern in English. The first sound is a voiced velar fricative /ɡ/, followed by a diphthong of /aʊ/ (as in "out"). The final sound is a voiced dental fricative /ð/. So, the proper way to spell it is "goundou." The IPA phonetic transcription for this word is /ˈɡaʊnduː/. With these guidelines, you can make sure to spell "goundou" correctly every time.
Henpuye, anakhre; a disease, endemic in West Africa, characterized by exostoses from the nasal processes of the maxillary bones producing a symmetrical swelling on each side of the nose.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.