You can call them ***abecedarian words***.

Abecedarian is an adjective meaning "being arranged alphabetically". It comes from the Latin *abecedarius*, which means "alphabetical," based on the names of the first letters of the Latin alphabet.

For example, below are the terms mentioned in a personal site:

> **Abecedarian Words:** Words with letters in alphabetical order <br> **Strictly Abecedarian Words:** Words with letters in alphabetical order without repetitions

><sub>http://www.tanyakhovanova.com/</sub>

It is also mentioned in this stackoverflow question: <br>
[Counting abecedarian words in a list: Python](http://stackoverflow.com/questions/9967395/counting-abecedarian-words-in-a-list-python)