The most common and most likely answer to this crossword clue is the 8 letter word BELGRADE
I've seen this crossword clue in The Guardian
B
E
L
G
R
A
D
E
More clues leading to the result BELGRADE
- Sound measure by which to rank European city
- Fertility god standing in capital city
- Be left standing in foreign city
- Capital, sixty percent below standard
- It was Byzantine, garbled, convoluted and ultimately intricate
- The Spanish invested in second-rate capital
- Glad beer is brewed by the Danube
- Large bed ordered? Capital!
- Badly garbled direction to reach capital
- Be left standing in capital city
Buddy explains!
The straight part
We know that "by the Danube" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case by the danube = belgrade.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.