Changes cautioned in teaching (9)
I believe the answer is:
education
'teaching' is the definition.
(I know that teaching can be written as education)
'changes cautioned' is the wordplay.
'changes' is an anagram indicator.
'cautioned' anagrammed gives 'EDUCATION'.
'in' is the link.
(Other definitions for education that I've seen before include "Teaching process" , "Academy's aim" , "studies" , "Theory and practice of teaching" , "an answer to all clues, initially" .)