First half allocation destroyed in the pub! (5)
I believe the answer is:
local
'the pub' is the definition.
(one's local pub)
'first half allocation destroyed' is the wordplay.
'first half' suggests halving the letters.
'destroyed' indicates anagramming the letters.
'allocation' cut in half is 'alloc'.
'alloc' is an anagram of 'LOCAL'.
'in' acts as a link.
(Other definitions for local that I've seen before include "where the neighbours drink?" , "Hostelry" , "Restricted number" , "Neighbourhood pub or resident" , "Relating to the neighbourhood" .)