Distant quality of a lesson varies (9)
I believe the answer is:
aloofness
'distant quality' is the definition.
The answer and definition can be both human attributes as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'of a lesson varies' is the wordplay.
'varies' is an anagram indicator.
'of'+'a'+'lesson'='ofalesson'
'ofalesson' anagrammed gives 'ALOOFNESS'.
Can you help me to learn more?
(Other definitions for aloofness that I've seen before include "Haughty nature" , "Cool and distant manner" , "Indifference by personal withdrawal" , "Detachment" , "Indifference, reserve" .)