The most common and most likely answer to this crossword clue is the 8 letter word BUDAPEST
B
U
D
A
P
E
S
T
More clues leading to the result BUDAPEST
- Shoot a persistently annoying person in capital
- Call up to have a trial for City
- City growth — a blight
- Shoot a troublemaker? Capital
- . Friend a right nuisance in this city
- Capital, dude, a nuisance
- US pal, a pain in the neck in European capital
- Friend takes off, having time in European city
- A nuisance having to chase American friend in European capital
- Capital’s pub with dates sorted out
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 = budapest.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.