Having kittens in hoarding outside fairground (6)
I believe the answer is:
afraid
'having kittens' is the definition.
I can't judge whether this definition defines the answer.
'hoarding outside fairground' is the wordplay.
'hoarding' becomes 'ad' (a hoarding is a board for advertisements).
'outside' means one lot of letters goes inside another.
'fairground' becomes 'frai' (I can't explain this - if you can you should believe this answer much more).
'ad' placed around 'frai' is 'AFRAID'.
'in' acts as a link.
Can you help me to learn more?
(Other definitions for afraid that I've seen before include "Fearful, anxious" , "cowardly" , "Scared - politely regretful" , "makes one panicky" , "wind up" .)