Learning of fraud occasionally in publication (9)
I believe the answer is:
erudition
'learning' is the definition.
(I know that learning can be written as erudition)
'fraud occasionally in publication' is the wordplay.
'occasionally' means one should take alternating letters (letters taken at regular intervals or occasions).
'in' indicates putting letters inside.
'publication' becomes 'edition' (edition is a kind of publication).
The alternate letters of 'fraud' are 'ru'.
'ru' placed within 'edition' is 'ERUDITION'.
'of' is the link.
(Other definitions for erudition that I've seen before include "Learning, scholarship" , "State of learning or culture" , "profound scholarly knowledge" , "being widely read" , "Great knowledge" .)