fly, why, try, my... The only one that I can think of that doesn't have the 'y' as a vowel is this word: Nth I believe the word means 'infinite'.
well, here is the link to the difinitions, it can mean either of the definitions that we posted: http://dictionary.reference.com/search?q=nth
Well, it never actually mentioned infinite. But, it does say the hightest, as in the highest of a series of numbers. If you made n=∞ then it would mean infinite. Although, the phrase to nth degree does often seem to signify infinite.
I see what you mean, invert. anyway, it doesn't have a vowel therefore it defies the English language!