Kitty starts with joke that's eccentric (8)
I believe the answer is:
crackpot
'eccentric' is the definition.
(I know that crackpot is a type of anorak)
'kitty starts with joke' is the wordplay.
'kitty starts' becomes 'pot' (I can't justify this - if you can you should believe this answer much more).
'with' says to put letters next to each other.
'joke' becomes 'crack' (a crack is a joke or quip).
'pot' put after 'crack' is 'CRACKPOT'.
'that's' is the link.
Can you help me to learn more?
(Other definitions for crackpot that I've seen before include "Mad" , "Ridiculous" , "crazy type" , "Bats" , "Foolish" .)