Not so much advanced education (6)
I believe the answer is:
lesson
'education' is the definition.
(lesson is a kind of education)
'not so much advanced' is the wordplay.
'not so' becomes 'less' (eg 'not so big' means 'less big').
'much advanced' becomes 'on' (I can't justify this - if you can you should believe this answer much more).
'less'+'on'='LESSON'
Can you help me to learn more?
(Other definitions for lesson that I've seen before include "School period" , "Reading or exercise for a pupil" , "Portion of instruction" , "Teaching session or reading from Bible" , "Church reading" .)