Abstemious ... and other uncommon words

There is something uncommon about the word abstemious. Do you know what it is?

It has all five vowels…in the right order.

not only that but in alphabetical order, and only once. Is it the shortest word that does that ?

Excellent! Do you know of any others?

facetiously - that one includes “y”

facetious
arsenious
caesious

[color=cyan]OK, I peeked.[/color]

[quote=“Dragonbones”]arsenious[/quote]You made that one up.

No, ask any chemist! It’s something containing arsenic, especially with valence 3.

[color=cyan]Ok, I had to look that up. [/color]