Put off by the deputy head being one of the family (5)
I believe the answer is:
daunt
'put off' is the definition.
(thesaurus)
'by the deputy head being one of the family' is the wordplay.
'by' says to put letters next to each other.
'head' suggests taking the first letters.
'being one of the family' becomes 'aunt' (I am not sure about this - if you are sure you should believe this answer much more).
The first letter of 'deputy' is 'd'.
'd'+'aunt' is 'DAUNT'.
Can you help me to learn more?
(Other definitions for daunt that I've seen before include "Make to feel intimidated" , "Cause to feel intimidated" , "Scare off - dismay" , "Cow" , "Discourage" .)