Care for teachers is head's part (7)
I believe the answer is:
cherish
'care for' is the definition.
(synonyms)
'teachers is head's part' is the wordplay.
'teachers' becomes 'cher' (I can't justify this - if you can you should believe this answer much more).
'part' indicates taking the first letters.
The first letter of 'heads' is 'h'.
'cher'+'is'+'h'='CHERISH'
Can you help me to learn more?
(Other definitions for cherish that I've seen before include "Protect and treat with affection" , "Foster" , "Nurse" , "Hold dear, treasure" , "Protect and care for lovingly" .)