Second jeer erupting on court (6)
I believe the answer is:
reject
'second' is the definition.
(thesaurus)
'jeer erupting on court' is the wordplay.
'erupting' is an anagram indicator.
'on' means one lot of letters go next to another.
'court' becomes 'ct'.
'jeer' is an anagram of 'reje'.
'reje'+'ct'='REJECT'
(Other definitions for reject that I've seen before include "Refuse to consider (something)" , "Unacceptable object" , "Renounce" , "substandard article" , "Repulse or repudiate" .)