Tolerate poet without second-class degree (8)
I believe the answer is:
standard
'degree' is the definition.
(I have seen 'Degree of quality' mean 'standard' so perhaps 'degree' could also mean 'standard')
'tolerate poet without second-class' is the wordplay.
'tolerate' becomes 'stand' (synonyms).
'poet' becomes 'bard' (bard is a kind of poet).
'without' is a deletion indicator.
'second class' becomes 'b'.
'bard' with 'b' taken away is 'ard'.
'stand'+'ard'='STANDARD'
(Other definitions for standard that I've seen before include "banner" , "Ceremonial flag" , "Normal; flag" , "'Reference point, touchstone (8)'" , "sort of lamp" .)