Roman statesman, one chilling in company (6)
I believe the answer is:
cicero
'roman statesman' is the definition.
(Cicero was a Roman statesman)
'one chilling in company' is the wordplay.
'one chilling' becomes 'icer' (someone or something that ices or chills).
'in' is an insertion indicator.
'company' becomes 'co' (abbreviation).
'icer' placed within 'co' is 'CICERO'.
(Other definitions for cicero that I've seen before include "Famous Roman orator" , "Marcus Tullius -, Roman consul, orator and writer" , "Philosopher" , "Roman lawyer" , "Roman orator and master of prose" .)