Footwear purchase in outdoor event (4,4)
I believe the answer is:
boot sale
'footwear purchase' is the definition.
I don't know anything about this answer so I can't tell whether it can be defined by this definition.
'outdoor event' is the wordplay.
'outdoor' becomes 'boot' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'event' becomes 'sale' (promotional event).
'boot'+'sale'='BOOT SALE'
'in' is the link.
Can you help me to learn more?
(Other definitions for boot sale that I've seen before include "Modern mini-business conducted from rear of car" , "Cheap market" .)