Bustling atmosphere around a short thoroughfare (5)
I believe the answer is:
astir
'bustling' is the definition.
(I've seen this in another clue)
'atmosphere around a short thoroughfare' is the wordplay.
'atmosphere' becomes 'asir' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'around' is an insertion indicator.
'a short' suggests taking the first letters.
The initial letter of 'thoroughfare' is 't'.
'asir' enclosing 't' is 'ASTIR'.
Can you help me to learn more?
(Other definitions for astir that I've seen before include "Starting to move" , "Busy" , "In a state of movement" , "Excitedly moving" , "This isn't still" .)