Accismus (pronounced ak-SIZ-muhs) is the rhetorical refusal of something one actually wants, to try and convince themselves or others of a different opinion. It is showing no interest in something while secretly wanting it. It’s a form of irony where one pretends indifference and refuses something while actually wanting it
An example from Aesop’s Fables:
Driven by hunger, a fox tried to reach some grapes hanging high on the vine but was unable to, although he leaped with all his strength. As he went away, the fox remarked ‘Oh, you aren’t even ripe yet! I don’t need any sour grapes.’ People who speak disparagingly of things that they cannot attain would do well to apply this story to themselves.