Admit everybody to the town centre (5)
I believe the answer is:
allow
'admit' is the definition.
(allowing is a kind of admiting)
'everybody to the town centre' is the wordplay.
'everybody' becomes 'all' (all people).
'to the town centre' becomes 'ow' (central letters of the word 'town').
'all'+'ow'='ALLOW'
(Other definitions for allow that I've seen before include "OK" , "Sanction" , "Permit, let happen" , "Permit or concede" , "Give leave to" .)