Homage a teacher keeps in proportion (9)
I believe the answer is:
adoration
'homage' is the definition.
(thesaurus)
'a teacher keeps in proportion' is the wordplay.
'teacher' becomes 'don' (don can mean an academic - especially at Oxbridge).
'keeps in' indicates putting letters inside.
'proportion' becomes 'ratio' (I've seen this before).
'don' going around 'ratio' is 'doration'.
'a'+'doration'='ADORATION'
(Other definitions for adoration that I've seen before include "Deep love and respect" , "Hero-worship" , "praise" , "Not a radio (anag.)" , "Honour" .)