Item left in car with sloping back (6)
I believe the answer is:
couple
'sloping back' is the definition.
The answer and definition can be both to do with social activities as well as being verbs in their base form.
Perhaps you can see a link between them that I can't see?
'item left in car' is the wordplay.
'item left' becomes 'l' (common abbreviation. I am not sure about the 'item' bit.).
'in' indicates putting letters inside.
'car' becomes 'coupe' (coupe is a kind of car).
'l' going within 'coupe' is 'COUPLE'.
'with' acts as a link.
Can you help me to learn more?
(Other definitions for couple that I've seen before include "Married pair; two forces causing rotation" , "Pair of attached people" , "Pair - put together" , "Unite" , "Bonnie and Clyde, say" .)