Missing the end off a bolt (4)
I believe the answer is:
awol
'missing' is the definition.
(military abbreviation for absent without leave)
'end off a bolt' is the wordplay.
'end off' means to remove the last letter.
'bolt' becomes 'wolf' (both can mean to eat something quickly).
'a'+'wolf'='awolf'
'awolf' with its last letter taken off is 'AWOL'.
'the' acts as a link.
(Other definitions for awol that I've seen before include "Take unofficial leave (abbrev.)" , "Absent without permission, in short" , "unaccounted for" , "Missing without permission" , "Absent without leave (abbrev.)" .)