About to enter, laugh out loud in pub (5)
I believe the answer is:
local
'pub' is the definition.
(one's local pub)
'about to enter laugh out loud' is the wordplay.
'about' becomes 'ca' (abbreviation for 'circa').
'to enter' indicates putting letters inside.
'laugh out loud' becomes 'LOL' (abbreviation).
'ca' put inside 'lol' is 'LOCAL'.
'in' acts as a link.
(Other definitions for local that I've seen before include "Public house - not far away" , "round the corner" , "belonging to particular area?" , "Stopping regularly" , "Confined to a place" .)