The most common and most likely answer to this crossword clue is the 8 letter word COLUMBIA
I've seen this crossword clue in The Guardian
C
O
L
U
M
B
I
A
More clues leading to the result COLUMBIA
- US district and country trades duck for uranium
- University in the country, say?
- It went into space in newspaper feature, leaning characters on right missing
- I’m not sure AC/DC will crack pop capital in USA
- Incomplete article on leaders of bureaucracy in American district
- Company-made album featuring one city
Buddy explains!
The straight part
We know that "US district" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case us district = columbia.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.