Presumably the male teacher should have it! (7)
I believe the answer is:
mastery
'presumably the male' is the definition.
I can't tell whether this defines the answer.
'teacher should have it' is the wordplay.
'teacher' becomes 'master' (I've seen this before).
'should have' means one lot of letters go next to another.
'it' becomes 'y' (I can't explain this - if you can you should believe this answer much more).
'master'+'y'='MASTERY'
Can you help me to learn more?
(Other definitions for mastery that I've seen before include "Supremacy" , "dominion" , "Comprehensive skill" , "Grasp" , "Comprehensive knowledge (of a subject)" .)