Maintain batting is over, stumped (6)
I believe the answer is:
insist
'maintain' is the definition.
(thesaurus)
'batting is over stumped' is the wordplay.
'batting' becomes 'in'.
'over' says the letters should be written backwards.
'stumped' becomes 'st' (I've seen this in other clues).
'is' back-to-front is 'si'.
'in'+'si'+'st'='INSIST'
(Other definitions for insist that I've seen before include "Persist in pressing" , "Be adamant" , "Press" , "Beg persistently and urgently" , "Be firm in demands" .)