Officers, material social creatures (9)
I believe the answer is:
sergeants
'officers' is the definition.
(sergeant is a kind of officer)
'material social creatures' is the wordplay.
'material' becomes 'serge' (serge is a kind of material).
'social creatures' becomes 'ants' (ant is a kind of creature. I am not sure about the 'social' bit.).
'serge'+'ants'='SERGEANTS'
Can you help me to learn more?
(Other definitions for sergeants that I've seen before include "Greatness observed in NCOs" , "Odd greatness of these army and police ranks" , "Greatness among NCOs" .)