Professors get me back to spirits (6)
I believe the answer is:
demons
'to spirits' is the definition.
(demon is a kind of spirit)
'professors get me back' is the wordplay.
'professors' becomes 'snod' (I can't justify this - if you can you should give a lot more credence to this answer).
'get' is an insertion indicator.
'back' says the letters should be written in reverse.
'snod' going around 'me' is 'snomed'.
'snomed' reversed gives 'DEMONS'.
Can you help me to learn more?
(Other definitions for demons that I've seen before include "Evil supernatural beings" , "Fiends or devils" , "Wicked people" , "Evil spirits, devils" .)