Cleaner is master, generating great presence (8)
I believe the answer is:
charisma
'great presence' is the definition.
'charisma' can be an answer for 'presence' (I've seen this in another clue). I'm not sure about the 'great' bit.
'cleaner is master' is the wordplay.
'cleaner' becomes 'char' (charwoman is a type of cleaner).
'master' becomes 'ma' (Master of Arts).
'char'+'is'+'ma'='CHARISMA'
'generating' is the link.
Can you help me to learn more?
(Other definitions for charisma that I've seen before include "something that fascinates many" , "quality inspiring devotion" , "power to influence" , "Divinely bestowed power" , "Personal magnetism -- archaism (anag)" .)