Case of excessive pride? (6)
I believe the answer is:
vanity
I believe this clue is a double definition.
'case' is the first definition.
(thesaurus)
'excessive pride?' is the second definition.
(I've seen this before)
'of' is the link.
(Other definitions for vanity that I've seen before include "Thackery was the author of ''. . . . . . Fair''" , "Futility; conceit" , "Excessive pride in one's self" , "Narcissism" , "Conceit; pointlessness" .)