Cancel, getting OK to be replaced by university show (5)
I believe the answer is:
revue
'show' is the definition.
(revue is a kind of show)
'cancel getting ok to be replaced by university' is the wordplay.
I cannot really see how this works, but
'getting' could be 're' (I've seen this in other clues) and 're' is found within the answer.
'university' could be 'u' (abbreviation for university) and 'u' is found within the answer.
This explanation may well be incorrect...
(Other definitions for revue that I've seen before include "Topical-sketch show" , "Song and dance entertainment" , "Kind of show with sketches and songs" , "Entertainment consisting of sketches" , "Stage entertainment with sketches, songs and dance" .)