Judge fools smugly, initially (6)
I believe the answer is:
assess
'judge' is the definition.
(assessing is a kind of judging)
'fools smugly initially' is the wordplay.
'fools' becomes 'asses' (ass is a kind of fool).
'initially' indicates taking the first letters.
The first letter of 'smugly' is 's'.
'asses'+'s'='ASSESS'
(Other definitions for assess that I've seen before include "Judge the worth of something" , "Remedy for all ills" , "Test" , "Estimate, gauge" , "Rate, evaluate" .)