Commonplace sound of spring around river (6)
I believe the answer is:
boring
'commonplace' is the definition.
'sound of spring around river' is the wordplay.
'sound of spring' becomes 'boing' (onomatopoeic representation of a spring's sound).
'around' indicates putting letters inside.
'river' becomes 'r'.
'boing' enclosing 'r' is 'BORING'.
(Other definitions for boring that I've seen before include "Tedious, tiresome" , "Drilling - it's monotonous" , "Mentally wearying" , "Dull and repetitive, a turn-off" , "Tedious and tiring" .)