Sort of box to be returned after delivery (6)
I believe the answer is:
ballot
'sort of box' 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 they are linked in a way I don't understand?
'to be returned after delivery' is the wordplay.
'be returned' says the letters should be written in reverse (I've seen 'is returned' mean this).
'after' is a charade indicator (letters next to each other).
'delivery' becomes 'ball' (ball is a kind of delivery).
'to' back-to-front is 'ot'.
'ot' put after 'ball' is 'BALLOT'.
Can you help me to learn more?
(Other definitions for ballot that I've seen before include "Document listing voting alternatives" , "Plebiscite" , "The process of voting" , "Document listing the alternatives to vote for" , "The process of exercising 20 Down" .)