What is diagestic?

"Diagestic" appears to be a misspelling or a typographical error. If you meant "diegetic," it refers to elements that exist within the narrative world of a story, such as characters, events, and settings that the characters are aware of. In contrast, "nondiegetic" elements, like background music or voiceovers, are not part of the story's world and are typically used for the audience's experience. If you meant something else, please clarify!