Part of the goal is to traverse the pub (8)
I believe the answer is:
crossbar
'part of the goal' is the definition.
('crossbar' is part of 'goal')
'traverse the pub' is the wordplay.
'traverse' becomes 'cross' ('cross' can be a synonym of 'traverse').
'the pub' becomes 'bar' (I've seen this before).
'cross'+'bar'='CROSSBAR'
'is to' is the link.
(Other definitions for crossbar that I've seen before include "It's over the goalie's head" , "what one may tip over?" , "Helps to define the goal" , "member over goal" , "Horizontal part of a goal" .)