Carry a kid to the back of the queue (4)
I believe the answer is:
tote
'carry' is the definition.
(toting is a kind of carrying)
'a kid to the back of the queue' is the wordplay.
'a kid' becomes 'tot' (tot is a kind of kid**).
'to the back of' says to take the final letters.
The final letter of 'queue' is 'e'.
'tot'+'e'='TOTE'
(Other definitions for tote that I've seen before include "Carry (a gun)" , "system that could be for the better" , "hump" , "Large bag" , "Carry; betting device" .)