Kick (4)
'kick' is the definition.
(I know that kick can be written as boot)
This is the entire clue.
(Other definitions for boot that I've seen before include "Kick; start (a computer)" , "They call it a trunk in the US" , "Kick; footwear" , "Hard kick (colloq.)" , "may be packed for a journey" .)
(Other definitions for punt that I've seen before include "What the Irish used" , "Open flat-bottomed boat" , "Pre-euro currency unit of Ireland" , "taken by a better" , "old money abroad" .)