The most common and most likely answer to this crossword clue is the 8 letter word KHARTOUM
I've seen this crossword clue in The Times
K
H
A
R
T
O
U
M
More clues leading to the result KHARTOUM
- Part of old bangers’ graveyard sounded capital
- African capital where an old banger may end up, do we hear?
- In the distance, see author struggling to get capital
- Running amok, Ruth Gordon bought it here
- City announces where they buried Clio?
- African capital reportedly a graveyard for drivers?
- Mark turned up with new author that’s penned ‘Gordon woz ‘ere’
- Film‘s a knockout, featuring Miranda and… I’m not sure
- Mark out ground in which to place hospital in capital
Buddy explains!

The straight part
We know that "African capital" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case african capital = khartoum.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.