Origin: Latin suffix -al
Alphabetical has 3 different meanings across 1 category:
relating to or expressed by a writing system that uses an alphabet
"alphabetical writing system"
arranged in order according to the alphabet
"an alphabetic arrangement"
"dictionaries list words in alphabetical order"
Pertaining to, furnished with, or expressed by letters of the alphabet.
"The librarian organized all the new arrivals in alphabetical order so that every patron could find their desired book easily."
In plain English: Alphabetical means things are arranged in order from A to Z based on their letters.
"The library books are arranged in alphabetical order on the shelves."
Usage: Use "alphabetical" to describe items arranged in order from A to Z, such as a dictionary or a contact list sorted by last name. Do not use it to mean simply written with letters, since all text is inherently composed of the alphabet.
The word comes from the Latin alphabēticus, which was formed by adding a suffix to alphabetum. It entered English to describe anything arranged in the order of the letters of the alphabet.