One with a degree of partially smug radicalism, (4)
I believe the answer is:
grad
'one with a degree' is the definition.
(I've seen this in another clue)
'partially smug radicalism' is the wordplay.
'partially' indicates a hidden word.
'GRAD' can be found hidden inside 'smug radicalism'.
'of' is the link.
(Other definitions for grad that I've seen before include "University degree holder (colloq.)" , "Person with a degree (informal)" , "Ex-student" , "One who studied" .)