Judge dispatched — for this reason start of hearing is cancelled (8)
I believe the answer is:
sentence
'judge' is the definition.
(I've seen this before)
'dispatched for this reason start of hearing is cancelled' is the wordplay.
I cannot quite understand how this works, but
'dispatched' could be 'sent' (I've seen this before) and 'sent' is present in the answer.
This may be the basis of clue (or it may be nonsense).
(Other definitions for sentence that I've seen before include "Grammatical unit and prison term" , "String of words or term in prison" , "life perhaps" , "Judicial penalty" , "in so many words" .)