River through four national capitals (6)

I believe the answer is:

danube

(Other definitions for danube that I've seen before include "Viennese river" , "Ban due (anag) - river" , "South European river" , "River flowing from Black Forest to Black Sea" , "flower" .)

I've seen this clue in The Wall Street Journal.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.