Smart Conservative greeting another (4)
I believe the answer is:
chic
'smart' is the definition.
(both can mean stylish)
'conservative greeting another' is the wordplay.
'conservative' becomes 'C' (UK political abbreviation).
'greeting' becomes 'hi' (hi is a kind of greeting).
'another' becomes 'c' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'c'+'hi'+'c'='CHIC'
Can you help me to learn more?
(Other definitions for chic that I've seen before include "Stylish and elegant - in France" , "Fashionably smart" , "A la mode" , "Unwanted sounds" , "Fashionably elegant" .)