1. 按字母顺序的；字母（表）的
Alphabetical means arranged according to the normal order of the letters in the alphabet.

1. arranged in order according to the alphabet

e.g. an alphabetic arrangement
dictionaries list words in alphabetical order

Synonym: alphabetic

2. relating to or expressed by a writing system that uses an alphabet

e.g. alphabetical writing system

Synonym: alphabetic