Former barrister maybe killing time sees model (8)
I believe the answer is:
exemplar
'model' is the definition.
(synonyms)
'former barrister maybe killing time' is the wordplay.
I cannot quite understand how this works, but
'former' could be 'ex' (prefix meaning former or onetime) and 'ex' is found within the answer.
This may be the basis of clue (or it may be nonsense).
'sees' acts as a link.
Can you help me to learn more?
(Other definitions for exemplar that I've seen before include "A model or instance" , "Epitome" , "Typical specimen" , "A good model or type" , "Model to be followed" .)