Alicorns · 9:20pm Nov 7th, 2016
"To digress for a moment, in the Equestrian language, the term alicorn can refer to any of, first, the thaumatically-active substance making up the core of an alicorn (sense 2) and certain other bony structures; second, the bony spiral horn of a unicorn or alicorn (sense 3); or, third, the rare sub-species of pony manifesting the combined traits of the three major sub-species, notable for possessing thereby the largest alicorns (sense 2) and the largest proportionate quantity of alicorn (sense 1).
"What this means is that over the course of centuries of magical research, many someponies have had to, at some point, utter the phrase 'the alicorn of an alicorn's alicorn' without cracking a smile or bursting into a fit of the giggles, something this researcher has found herself entirely unable to do. How this has never led to any change in these various usages is a mystery probably exceeding the grasp of even the Department of Pinkieology."
- from an unpublished draft of the notes of Cordelia "Moongleam" Vintar-ith-Vidutar
Hahaha! I wondered the very same thing!