The letter z.
[Probably variant of Scots ezed, variant of ZED.]
Word History: The curious and charming word izzard, meaning "the letter z," is practically limited to certain fixed expressions in American vernacular English, such as from A to izzard, "from beginning to end," and not to know A from izzard, "not to know even the most basic things." The English lexicographer Samuel Johnson mentions the word izzard as part of his attempt to explain the sound of the letter z in the grammar of English he placed at the beginning of his Dictionary of the English Language, published in 1755: Z begins no word originally English; it has the sound, as its name izzard ... expresses, of an s uttered with a closer compression of the palate. In Johnson's time, a variant name for the letter z, uzzard, was also in use. Izzard and uzzard are related to zed, the usual name of the letter z in British English. In Scottish English, z was also once known as ezed, and this form gives us a clue to a possible origin of izzard. The name may have developed from the phrase pronounced at the end of a recitation of the alphabet in Old French, et zede, "and zed" ("and zee" in American English). The Old French word for the letter z, zede, descends from Late Latin zēta, and the Late Latin word itself goes back to the name used by the Greeks for their letter ζ, zēta.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2022 by HarperCollins Publishers. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.