Today I came across a word I've never
seen or heard before: illabial. I would guess that it's the same thing as
unrounded, but I prefer information to guesses. It says in a book that the
sound written <õ> in Estonian (which I don't know) is "ein
illabialer mittelhoher Mittelvokal" — [ə]?
Can anyone confirm this?
From the description it's quite clear that the intended meaning is
'non-labial', but I can't recall ever coming across this adjective (there is
no 'invelar' or 'indental' either). A learned nonce-word, most likely.