Slump, depressed, next to item in playground (9)
I believe the answer is:
downswing
'slump' is the definition.
(thesaurus)
'depressed next to item in playground' is the wordplay.
'depressed' becomes 'down' (synonyms).
'next to' is a charade indicator (letters next to each other).
'item in playground' becomes 'swing' (a swing set).
'down'+'swing'='DOWNSWING'
(Other definitions for downswing that I've seen before include "trend towards recession?" , "Part of drive" , "decline" , "worsening of economy" .)