Posts support this angry poet for the most part (8)
I believe the answer is:
crossbar
'posts support this' is the definition.
(goalposts hold up the crossbar)
'angry poet for the most part' is the wordplay.
'angry' becomes 'cross' (cross can mean annoyed or angry).
'poet' becomes 'bard' (bard is a kind of poet).
'for the most part' means to remove the last letter.
'bard' with its final letter taken away is 'bar'.
'cross'+'bar'='CROSSBAR'
(Other definitions for crossbar that I've seen before include "one's seen on a bike?" , "Bit of sports equipment" , "One of two on football field" , "member over goal" , "Horizontal beam over goal posts" .)