Clear spring after flowed into river (11)
I believe the answer is:
transparent
'clear' is the definition.
(similar in meaning)
'spring after flowed into river' is the wordplay.
I cannot really see how this works, but
'spring' could be 'spa' (spa can mean a mineral spring) and 'spa' is located in the answer.
'flowed' could be 'ran' ('run' can be a synonym of 'flow') and 'ran' is found within the answer.
'river' could be 'trent' (River Trent) and 'trent' is located in the remaining letters.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for transparent that I've seen before include "poor at lying" , "See-through - easily understood" , "Lucid - evident - clear" , "Unpolluted" , "unmistakable" .)