Z, z

[zee or, esp. British, zed; Archaic iz-erd]

noun, plural Z's or Zs, z's or zs.

the 26th letter of the English alphabet, a consonant.
any spoken sound represented by the letter Z or z, as in zero, zigzag, or buzzer.
something having the shape of a Z.
a written or printed representation of the letter Z or z.
a device, as a printer's type, for reproducing the letter Z or z.



Symbol, Mathematics.

an unknown quantity or variable.
(in Cartesian coordinates) the z-axis.


Astronomy. zenith distance.



the 26th in order or in a series, or, when I is omitted, the 25th.
(sometimes lowercase) the medieval Roman numeral for 2000.Compare Roman numerals.
Chemistry, Physics. atomic number.
Electricity. impedance.


Symbol, Physics. Z-zero particle.



or Z's


noun (used with a plural verb) Slang.

sleep (often used with grab, catch, etc.): to grab some z's before dinner.

Origin of z's

First recorded in 1960–65; from the conventional use of a series of z's to represent snoring


[zey-tuh, zee-]


the sixth letter of the Greek alphabet (Z, ζ).
the consonant sound represented by this letter.

Origin of zeta

First recorded in 1820–30, zeta is from the Greek word zêta
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for z

Contemporary Examples of z

Historical Examples of z

  • Its planks were oak; great nails in them marked the Z of its brace.

  • "Two" often appears as z in the early printed books, 12 appearing as iz.

    The Hindu-Arabic Numerals

    David Eugene Smith

  • He was amazed to learn that she had walked all the way from Z——, and quite alone, too.

  • And we have witnesses that Kettle-Belly was in some kind of deal with the z'Srauff, too.

    Lone Star Planet

    Henry Beam Piper and John Joseph McGuire

  • Yes, plus anybody whom the z'Srauff Ambassador might have told.

    Lone Star Planet

    Henry Beam Piper and John Joseph McGuire

British Dictionary definitions for z


symbol for

the z- axis or a coordinate measured along the z- axis in a Cartesian or cylindrical coordinate system
an algebraic variable



noun plural z's, Z's or Zs

the 26th and last letter and the 20th consonant of the modern English alphabet
a speech sound represented by this letter, in English usually a voiced alveolar fricative, as in zip
  1. something shaped like a Z
  2. (in combination)a Z-bend in a road


symbol for

any unknown, variable, or unspecified factor, number, person, or thing
chem atomic number
physics impedance
currency zaïre

abbreviation for

Zambia (international car registration)



the sixth letter in the Greek alphabet (Ζ, ζ), a consonant, transliterated as z

Word Origin for zeta

from Greek, of Semitic origin; compare Hebrew sādhē



(foll by the genitive case of a specified constellation) the sixth brightest star in a constellationZeta Tauri



a torus-shaped apparatus used for research in the 1950s and early 1960s on controlled thermonuclear reactions and plasma physics

Word Origin for ZETA

C20: from z (ero-) e (nergy) t (hermonuclear) a (pparatus)
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for z


not a native letter in Old English; in Anglo-French words it represents the "ts" sound (e.g. Anglo-French fiz, from Latin filius, modern Fitz); from late 13c. it began to be used for the voiced "s" sound and had fully taken that role by 1400. For letter name, see zed.

Thou whoreson Zed, thou vnnecessary Letter. ["King Lear," II.ii.69]

Series of zs to represent a buzzing sound first attested 1852; zees "spell of sleep, a nap" is slang first recorded 1963, American English student slang.


Greek letter, see zed.

Online Etymology Dictionary, © 2010 Douglas Harper

Medicine definitions for z


[zātə, zē-]


The sixth letter of the Greek alphabet.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Idioms and Phrases with z


see from soup to nuts (a to z).

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.