Lots mill about in fringes of jamboree or push and shove (6)
I believe the answer is:
jostle
'push and shove' is the definition.
(I've seen this in another clue)
'lots mill about in fringes of jamboree' is the wordplay.
'lots mill about' becomes 'ostl' (I can't explain this - if you can you should give a lot more credence to this answer).
'in' indicates putting letters inside.
'fringes of' says to hollow out the word (remove centre letters).
'jamboree' with its middle taken out is 'je'.
'ostl' going inside 'je' is 'JOSTLE'.
'or' is the link.
Can you help me to learn more?
(Other definitions for jostle that I've seen before include "Bump and push (for position)" , "Pushing and shoving" , "jockey" , "Push and elbow roughly in a crowd" , "Push or bump roughly against someone" .)