Surprised if you included school (5)
I believe the answer is:
edify
'school' is the definition.
(thesaurus)
'surprised if you included' is the wordplay.
'included' says the answer is hidden in the clue (I've seen 'including' mean this).
'EDIFY' is hidden in the letters of 'surprised if you'.
(Other definitions for edify that I've seen before include "Uplift; elevate" , "Improve (someone) morally or intellectually" , "Improve the mind (of)" , "Strengthen spiritually" , "Improve morality, perhaps" .)