Order given by teachers (11)
I believe the answer is:
instruction
'order given by teachers' is the definition.
'instruction' can be an answer for 'order' (I've seen this before). I am not certain of the 'given by teachers' bit.
'order given by teachers' is the wordplay.
'order' becomes 'instruct' (instructing is a kind of ordering).
'given by teachers' becomes 'ion' (I can't explain this - if you can you should give a lot more credence to this answer).
'instruct'+'ion'='INSTRUCTION'
Can you help me to learn more?
(Other definitions for instruction that I've seen before include "Teaching" , "summons?" , "Training" , "Teacher's job" , "Direction, order" .)