Not a street where things happen (5)
I believe the answer is:
venue
'where things happen' is the definition.
'not a street' is the wordplay.
'not' is a deletion indicator.
'street' becomes 'avenue' (avenue is a kind of street).
'avenue' with 'a' removed is 'VENUE'.
(Other definitions for venue that I've seen before include "Meeting-place" , "Chosen location" , "Place for organised event" , "Something is happening here" , "Event's location" .)