Circulation editor becoming late (7)
I believe the answer is:
eddying
'circulation editor becoming late' is the definition.
I can't judge whether this definition defines the answer.
'editor becoming late' is the wordplay.
'editor' becomes 'ed' (abbreviation).
'becoming late' becomes 'dying' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'ed'+'dying'='EDDYING'
Can you help me to learn more?
(Other definitions for eddying that I've seen before include "in vortex" , "Swirling around" , "Swirling round" .)