Sort of guess a graduate might make? (8)
I believe the answer is:
educated
'sort of guess' is the definition.
(an educated guess)
I don't understand how the rest of the clue works.
(Other definitions for educated that I've seen before include "Schooled, trained" , "Instructed, taught" , "Enlightened, knowledgeable" , "Trained; learned" , "Well-read" .)