River that can be seen to be losing volume, which is ludicrous (7)
I believe the answer is:
risible
'ludicrous' is the definition.
(I've seen this in another clue)
'river that can be seen to be losing volume which is' is the wordplay.
I cannot really see how this works, but
'river' could be 'r' (abbreviation for river) and 'r' is present in the answer.
'is' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for risible that I've seen before include "Laughable, amusing" , "Laughable, really ridiculous" , "Producing amusement" , "Provoking laughter" , "Laughter-provoking" .)