Teacher dismissing of supporting work one dictates (9)
I believe the answer is:
oppressor
'one dictates' is the definition.
(oppressor could mean a dictator)
'teacher dismissing of supporting work' is the wordplay.
I cannot quite understand how this works, but
'of' could be 'o' and 'o' is present in the answer.
'work' could be 'press' (press is a kind of work) and 'press' is present in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for oppressor that I've seen before include "Tyrant" , "One subjects others to undue pressure" , "Proposers for one who persecutes" , "One who keeps another in subjection" , "Persecutor of proposers" .)