Sorcery of African people on the up (3)
I believe the answer is:
obi
'sorcery' is the definition.
(I know that obi is a type of sorcery)
'african people on the up' is the wordplay.
'african people' becomes 'ibo' (the Ibo or Igbo people of Nigeria).
'on the up' says the letters should be written backwards (in a down clue, letters go up).
'ibo' reversed gives 'OBI'.
'of' acts as a link.
(Other definitions for obi that I've seen before include "Japanese sash - African witchcraft" , "Sash worn on Japanese kimono" , "Long cloth" , "Kimono accessory" , "sash from Tokyo" .)