The sport one is packing up? (6)
I believe the answer is:
boxing
'the sport' is the definition.
(boxing is a kind of sport)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for boxing that I've seen before include "The noble art?" , "Pugilist's sport" , "Fighting with the fists" , "Ring sport" , "Fighting in a ring" .)