Having seats outside mean not being together (9)
I believe the answer is:
separated
'not being together' is the definition.
I can't judge whether this definition defines the answer.
'having seats outside mean' is the wordplay.
'having seats' becomes 'seated' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'outside' indicates putting letters inside.
'mean' becomes 'par' (I've seen this in other clues).
'seated' placed around 'par' is 'SEPARATED'.
Can you help me to learn more?
(Other definitions for separated that I've seen before include "Split" , "in different cages?" , "Broke up" , "Pulled apart" , "Distinguished -- divided" .)