Street is a place for activity (6)
I believe the answer is:
avenue
'street' is the definition.
(I know that avenue is a type of street)
'a place for activity' is the wordplay.
'place for activity' becomes 'venue' (eg the place for a meeting).
'a'+'venue'='AVENUE'
'is' is the link.
(Other definitions for avenue that I've seen before include "Broad road or street, often with trees" , "Road leading to a house" , "Wide street or road as in New York" , "Tee-lined road" , "Road lined with trees" .)