Surrender, wobbling one run short of century, ending on ninety-nine (8)
I believe the answer is:
renounce
'surrender' is the definition.
(thesaurus)
'wobbling one run short of century ending on ninety-nine' is the wordplay.
'wobbling' indicates anagramming the letters.
'short of' says to take the initial letters (I've seen 'short' mean this).
'ending on ninety nine' becomes 'e' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
The first letter of 'century' is 'c'.
'one'+'run'='onerun'
'onerun' anagrammed gives 'renoun'.
'renoun'+'c'+'e'='RENOUNCE'
Can you help me to learn more?
(Other definitions for renounce that I've seen before include "Give up, abdicate" , "Disclaim or reject publicly" , "Give up, power say" , "Decide to forgo" , "Abandon, give up" .)