Follow a queue (4)
I believe the answer is:
tail
This clue is a double definition.
'follow' is the first definition.
(both can mean to chase or pursue)
'a queue' is the second definition.
(I've seen this before)
(Other definitions for tail that I've seen before include "Last, rear, part" , "that can be cast by a lizard" , "Comet's luminous trail" , "Shadow" , "Follow; end part" .)