Maybe no grin at being uneducated (8)
I believe the answer is:
ignorant
'uneducated' is the definition.
(similar in meaning)
'maybe no grin at' is the wordplay.
'maybe' indicates an anagram.
'no'+'grin'+'at'='nogrinat'
'nogrinat' is an anagram of 'IGNORANT'.
'being' is the link.
(Other definitions for ignorant that I've seen before include "Rude or knowing very little" , "Unaware, uninformed" , "Devoid of knowledge" , "Unlearned, lacking knowledge" , "Crass" .)