Team of leaderless infants lifting barrier (9)
I believe the answer is:
wallabies
'team' is the definition.
(nickname for Australian national rugby union team)
'leaderless infants lifting barrier' is the wordplay.
'leaderless' means to remove the first letter.
'infants' becomes 'babies' ('baby' can be a synonym of 'infant').
'lifting' means one lot of letters go next to another.
'barrier' becomes 'wall' (I've seen this before).
'babies' with its initial letter taken off is 'abies'.
'abies' after 'wall' is 'WALLABIES'.
'of' acts as a link.
(Other definitions for wallabies that I've seen before include "Marsupials" , "bounders" , "Pouched jumpers" .)