Second best stall (4)
I believe the answer is:
stop
'stall' is the definition.
(thesaurus)
'second best' is the wordplay.
'second' becomes 's' (common abbreviation).
'best' becomes 'top' ('top' can be similar in meaning to 'best').
's'+'top'='STOP'
(Other definitions for stop that I've seen before include "Pack it in - bar" , "Check" , "oboe, perhaps" , "Hold on" , "Withhold large amount raised" .)