A team order that’s generally accepted (5)
I believe the answer is:
axiom
'that's generally accepted' is the definition.
(a generally accepted principle or truth)
'a team order' is the wordplay.
'team' becomes 'xi' (eleven, a football team).
'order' becomes 'om' (Order of Merit).
'a'+'xi'+'om'='AXIOM'
(Other definitions for axiom that I've seen before include "Accepted general truth or principle" , "Maxim, aphorism" , "Clearly true statement" , "Old saying or precept 95)" , "truthful statement" .)