Well, preferably not a molecule that appears in a reference book for chemists--like the 1,185 character-long description of a Tobacco mosaic virus that begins "Glutaminylphenyl..." and continues on and on and on for a paragraph. Krulwich concludes that, yes, a word has to be "used" at some point to actually count as "real." So here's what he settles on, courtesy of a book by Sam Kean:
Pneumonoultramicroscopicsilicovolcanokoniosis. Krulwich's simple definition: "It's a disease." But, unfortunately, that's as unsatisfying as "Glutaminyl..." because it's still "technical" jargon. Can't the crown be given to word that isn't technical and isn't "fragilistic..."? Sadly, the answer appears to be "No."
While Krulwich ends up solidifying the Poppins term's position, the Wire hopes that someone finds a way to add a 7 more letters to the 28 character antidisestablishmentarianism--just to wrestle away the crown.
[H/T: The Morning News]