from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A sentence that uses all the letters of the alphabet.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A sentence that contains every letter of the alphabet, such as "The quick brown fox jumps over the lazy dog" in English.
From Ancient Greek παν ("everything") + γράμμα ("letter"), thus "all letters". (Wiktionary)