Split after admitting mistake that raised yield (9)
I believe the answer is:
surrender
'yield' is the definition.
(yield can mean to give up or surrender)
'split after admitting' is the wordplay.
'split' becomes 'rend' (rend can mean to split or tear).
'after' becomes 'surer' (I am not sure about this - if you are sure you should believe this answer much more).
'admitting' indicates putting letters inside (admit can mean to welcome in or accept).
'rend' put into 'surer' is 'SURRENDER'.
'mistake that raised' acts as a link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for surrender that I've seen before include "Hand over" , "Yield - release" , "Resign" , "Yield to the control of another" , "Cede" .)