Alien to greet Conservative with set of moral values (5)
I believe the answer is:
ethic
'set of moral values' is the definition.
(I've seen this in another clue)
'alien to greet conservative' is the wordplay.
'alien' becomes 'et' (extra terrestrial).
'to greet conservative' becomes 'hic' (I can't explain this - if you can you should give a lot more credence to this answer).
'et'+'hic'='ETHIC'
'with' acts as a link.
Can you help me to learn more?
(Other definitions for ethic that I've seen before include "set of morals" , "Moral system" , "Moral rule" , "Set of moral principles" , "System of rules of behaviour" .)