African diary grandmother keeps up (7)
I believe the answer is:
angolan
'african' is the definition.
(Angolan is an example)
'diary grandmother keeps up' is the wordplay.
'diary' becomes 'log' (log can mean a record or diary).
'grandmother' becomes 'nana' (I've seen this before).
'keeps' is an insertion indicator (inserted letters are kept inside).
'up' is a reversal indicator (in down clue: letters go upwards).
'log' going inside 'nana' is 'nalogna'.
'nalogna' reversed gives 'ANGOLAN'.
(Other definitions for angolan that I've seen before include "from Africa" , "One from Luanda" , "Coming from a southwest African country" , "Eg, native of Luanda" .)