Make up rubbish chapter as academic (6)
I believe the answer is:
doctor
'academic' is the definition.
(doctor can mean someone with a doctorate)
'make up rubbish chapter' is the wordplay.
'make' becomes 'do' (do can mean to make or prepare).
'up' shows that the letters should be reversed in order (in down clue: letters go upwards).
'rubbish' becomes 'rot' (both can mean nonsense).
'chapter' becomes 'c' (abbreviation).
'rot'+'c'='rotc'
'rotc' reversed gives 'ctor'.
'do'+'ctor'='DOCTOR'
'as' is the link.
(Other definitions for doctor that I've seen before include "Medical practitioner, for instance" , "Falsify; quack" , "One seeing cases" , "Who, for example" , "Foster, Who, Jekyll or Livingstone" .)