Open-minded, English lot over tirade (8)
I believe the answer is:
tolerant
'open-minded' is the definition.
(I've seen this in another clue)
'english lot over tirade' is the wordplay.
'english' becomes 'E' (abbreviation as in OED).
'over' says the letters should be written backwards.
'tirade' becomes 'rant' (both can mean an angry outburst).
'e'+'lot'='elot'
'elot' back-to-front is 'tole'.
'tole'+'rant'='TOLERANT'
(Other definitions for tolerant that I've seen before include "Indulgent, permissive" , "Broadminded, acceptance of others' beliefs" , "Forgiving" , "Accepting of others' ways" , "Patient, forbearing" .)