Liaison with cat is terribly unfriendly (10)
I believe the answer is:
antisocial
'unfriendly' is the definition.
Both the definition and answer are adjectives. Maybe there's a link between them I don't understand?
'liaison with cat is terribly' is the wordplay.
'with' is a charade indicator (letters next to each other).
'is terribly' indicates anagramming the letters.
'liaison' after 'cat' is 'catliaison'.
'catliaison' is an anagram of 'ANTISOCIAL'.
Can you help me to learn more?
(Other definitions for antisocial that I've seen before include "Not getting on with others" , "Disruptive to the community" , "Reluctant to mix" , "Avoiding the company of others" , "Disinclined to mix" .)