A term used to describe something that is so abstract, intangible, or hypothetical that it exists only in theory or imagination and cannot be proven to exist in reality. It's a blend of "unexist" (not existing) and "ability" (the quality or state of being capable).
Person 1: "Do you think there's life on other planets?"
Person 2: "It's an intriguing question, but until we have concrete evidence, it remains in the realm of unexistability, existing only in our imaginations and scientific theories."
Fogey/fogy /fougi/ sl. (early 18C+, orig. Scot) old-fashioned, stuck-in-the mud.
Person with old fashioned ideas which he is unwilling to change: Come to the disco and stop being such an old fogey!
You think me an old fogeyand an old tory, his thoughtful voice said. I saw three generations since O’Connel’s time. I remember the famine. Do you know that the orange lodges agitated for repeal of the union twenty years before O’Connel did or before the prelates of your communion denounced him as a demagogue? You fenians forget some things. (James Joyce, Ulysses. Penguin Books,1992. p. 38)