To know how to say "sun" in a particular African language, you'd need to specify the language.
For example:
* Swahili (Tanzania, Kenya, Uganda): Jua
* Yoruba (Nigeria): Oòrùn
* Zulu (South Africa): Ilanga
* Amharic (Ethiopia): ፀሐይ (tsehay)
* Hausa (Nigeria, Niger): Rana
Let me know what language you'd like to know the word for "sun" in, and I can provide the translation.