Part of a goal (8)
I believe the answer is:
crossbar
'part of a goal' is the definition.
('crossbar' is part of 'goal')
This is all the clue.
(Other definitions for crossbar that I've seen before include "Post connecting goalposts" , "It may support rider" , "Goal's top member" , "Horizontal beam over goal posts" , "what one may tip over?" .)