The most common and most likely answer to this crossword clue is the 4 letter word BAKU
I've seen this crossword clue in The Sunday Telegraph
B
A
K
U
More clues leading to the result BAKU
- Luck maybe needed off and on to raise capital
- Capital city of this country backed by its airline
- Leaders of United Kingdom antagonised Brussels over capital
- Taken by Arab, a Kurdish capital
- A
- British sailor raised capital
- Reported dilemma for voters in capital city
- Blackout frequently cut off capital city
- Originally, banking authority kept using capital
- Capital in Nuuk abandoned after retreating
Buddy explains!
The straight part
We know that "capital" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case capital = baku.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.