I'm in the process of writing a fantasy-esque novel, and the current scene takes place during a funeral. Mal, Miranda, and Zan are discussing the people they've lost over the course of their lives. In Mal and Zan's case, those losses were the death of their wife and/or family, and relatively recent. In Miranda's case, it's a little more complicated. Without explaining the details of a complicated situation, Miranda's sister has ceased to exist. She did *not* die, I would like to specify; more like there's the mortal dimension, and then a series of other dimensions who serve other purposes. Miranda's sister has been relocated into one of these other dimensions, and if it weren't for the fact that the sister is very much not dead, she may as well be. When the sister was transferred to this other dimension, it was a very traumatic event for Miranda. She refers to the event as 'when I lost my sister'. When Zan asks her how her sister died, she says, "Never said she did." My question is this: what words can I use to describe the event of the sister's disappearance without saying 'death' or 'loss'? I can come up with a dozen synonyms for death, but none that are quite ambiguous enough to simply represent loss. I don't like using the same word four times in five sentences. Miranda probably would avoid that repetition herself, if she could choose her own words.
The word cession would straddle the line between dying and ceasing to exist. Example: "My sister experienced a cession of existence a while ago." "How did she die?" Zan asked. "I never said she did." This should work for the verbal sleight of hand you want to play on the reader in this part of the story.
noun: cession; plural noun: cessions the formal giving up of rights, property, or territory by a state. Perhaps cessation?