Maybe Busby suffered from terrible rage about Everton's opener (8)
I believe the answer is:
headgear
'maybe busby' is the definition.
(busby is a type of military headgear )
'suffered from terrible rage about everton's opener' is the wordplay.
'suffered from' becomes 'had' ('have' can be a synonym of 'suffer from').
'terrible' is an anagram indicator.
'about' indicates putting letters inside.
'opener' says to take the initial letters.
The initial letter of 'everton' is 'e'.
'rage' is an anagram of 'gear'.
'had'+'gear'='hadgear'
'hadgear' going around 'e' is 'HEADGEAR'.
(Other definitions for headgear that I've seen before include "bowler, for example" , "cap, say" , "Hats, bonnets, caps etc" , "Hats, helmets etc." , "bowler perhaps" .)