Spooner's concealing bunny in equestrian clothing (6,5)
I believe the answer is:
riding habit
'clothing' is the definition.
(riding habit is a kind of clothing)
'spooner's concealing bunny in equestrian' is the wordplay.
I cannot really understand how this works, but
'in' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for riding habit that I've seen before include "What huntswoman assumes" , "Woman's clothing" , "pink dress" , "Equestrian dress" , "Custom of being on H [HORSE]" .)