Pertaining to, furnished with, or expressed by letters of the alphabet. / According to the sequence of the letters of the alphabet. / (obsolete) literal

The set of letters used when writing in a language.

(rare) To designate by the letters of the alphabet; to arrange alphabetically.

A standardized set of symbols for representing the sounds of human speech.

(nonstandard) the Devanagari writing system

(linguistics) The Glagolitic writing system, the oldest known Slavonic alphabet.

(US, Canada) To arrange words or items in order of the first (and then subsequent) letters as they occur in the alphabet.

The ICAO radiotelephony spelling alphabet of the International Civil Aviation Organization. This alphabet assigns names to letters of the alphabet for clearer enunciation (and for the same reason pronounces the numeral 9 as "niner"):

Of or relating to an alphabet, especially the characters A to Z, both uppercase and lowercase.

A writing system used to unambiguously transcribe the sounds of human speech.