Bury, surrender or step in (9)
I believe the answer is:
intercede
'step in' is the definition.
(I've seen this before)
'bury surrender' is the wordplay.
'bury' becomes 'inter' (to inter is to put into the ground).
'surrender' becomes 'cede' (synonyms).
'inter'+'cede'='INTERCEDE'
'or' is the link.
(Other definitions for intercede that I've seen before include "Plead on behalf of another" , "step in" , "Act as peacemaker between two parties" , "Act between parties to reconcile differences" , "Intervene, on behalf of another" .)