Teaching session for corrupt tout - liar (8)
I believe the answer is:
tutorial
'teaching session' is the definition.
(I've seen this before)
'corrupt tout liar' is the wordplay.
'corrupt' indicates an anagram (a corrupted spelling of the word).
'tout'+'liar'='toutliar'
'toutliar' is an anagram of 'TUTORIAL'.
'for' acts as a link.
(Other definitions for tutorial that I've seen before include "Period of individual instruction" , "Conference" , "Study meeting" , "University study period" , "University lesson" .)