Not wearing as much shows class (6)
I believe the answer is:
lesson
'class' is the definition.
(I've seen this before)
'not wearing as much shows' is the wordplay.
'not' becomes 'less' (I've seen this in other clues).
'wearing as much shows' becomes 'on' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'less'+'on'='LESSON'
Can you help me to learn more?
(Other definitions for lesson that I've seen before include "Teaching session or Bible passage" , "Class session or reading from Bible" , "Church reading" , "corrective punishment" , "A sermon or tutorial" .)