Yesterday I mentioned that abstemious is one of only two words where all vowels appear in alphabetical order. It's a rarely used term, making up only 0.000016% of words used, basically meaning "not self-indulgent", often to do with food or drink (it's probably used less often because synonyms such as temperate or moderate can work just as well). The word was borrowed circa 1600 from Latin, where we can immediately chop off the ab- prefix (meaning "away from") and the -ous suffix, which denotes the presence of a quality. What's left is a mangled version of the root temetum, which in Latin was used to denote particularly strong drink, normally really powerful mead or wine. Etymologists are not absolutely certain what led up to that, but temetum could derive from Proto-Indo-European temh, meaning "dark", because the strong beverages in question were often quite dark.
Adam Aleksic has been described as the internet's sixth most famous etymologist. He loves writing about himself in the third person, he's a freshman at Harvard University, and he has disturbing interests in linguistics, vexillology, geography, board games, limericks, and law.
The Etymology Nerd