Judgement posted before Vice President loses power (8)
I believe the answer is:
sentence
'judgement' is the definition.
(sentence is a kind of judgement)
'posted before vice president loses power' is the wordplay.
I cannot really see how this works, but
'posted' could be 'sent' ('send' can be a synonym of 'post') and 'sent' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for sentence that I've seen before include "Punishment awarded by court, or a set of words" , "Court judgement" , "life perhaps" , "Judicial penalty" , "Period of imprisonment" .)