Lot of Catholics in return of Spring (6)
I believe the answer is:
parcel
'lot' is the definition.
(I've seen this in another clue)
'catholics in return of spring' is the wordplay.
'catholics' becomes 'rc' (I can't justify this - if you can you should give a lot more credence to this answer).
'in' is an insertion indicator.
'return of' shows that the letters should be reversed in order.
'spring' becomes 'leap' (both can mean to jump).
'leap' in reverse letter order is 'pael'.
'rc' placed into 'pael' is 'PARCEL'.
'of' acts as a link.
Can you help me to learn more?
(Other definitions for parcel that I've seen before include "Wrapped container" , "Wrapped present" , "'Bundle, package (6)'" , "Amount of land; package" , "Area of land" .)