Old statesman and Commander-in-Chief meeting Cockney super-guy (6)
I believe the answer is:
cicero
'old statesman' is the definition.
(Roman politician)
'commander-in-chief meeting cockney super-guy' is the wordplay.
'commander-in-chief' becomes 'CIC' (abbreviation).
'meeting' means one lot of letters go next to another.
'cockney super guy' becomes 'ero' (I can't justify this - if you can you should give a lot more credence to this answer).
'cic'+'ero'='CICERO'
'and' acts as a link.
Can you help me to learn more?
(Other definitions for cicero that I've seen before include "Old Roman statesman and orator" , "Roman orator, author" , "Roman lawyer" , "Roman orator; type size above pica" , "wartime spy" .)