Waterway another ban due (6)
I believe the answer is:
danube
'waterway' is the definition.
The definition and answer can be both natural objects as well as being singular nouns.
Perhaps you can see an association between them that I don't see?
'another ban due' is the wordplay.
'another' is an anagram indicator.
'ban'+'due'='bandue'
'bandue' is an anagram of 'DANUBE'.
Can you help me to learn more?
(Other definitions for danube that I've seen before include "It's blue according to the song" , "Great European river, musically blue (6)" , "flower" , "South European river" , "Vienna's river" .)