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noun Informal.
  1. infectious mononucleosis.

Origin of mono1

by shortening


  1. monophonic(def 2).

Origin of mono2

by shortening


  1. a combining form meaning “alone,” “single,” “one” (monogamy); specialized in some scientific terms to denote a monomolecular thickness (monolayer) and adapted in chemistry to apply to compounds containing one atom of a particular element (monohydrate).
Also especially before a vowel, mon-.

Origin of mono-

< Greek, combining form of mónos alone
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for mono

Contemporary Examples

Historical Examples

  • Mono, it is sometimes called, and sometimes the "Dead Sea of California."

    Roughing It

    Mark Twain (Samuel Clemens)

  • I am to join him at Mono Lake, and we shall go on from there to-night.

    Roughing It

    Mark Twain (Samuel Clemens)

  • From its summit one looks down on the Mono Desert, the lake, and the craters.

    Your National Parks

    Enos A. Mills

  • A trail to the right leads to Mono Meadow and the basin of the Illilouette.

  • MONO, which means one, is the simplest form of carbohydrates.

    Encyclopedia of Diet

    Eugene Christian

British Dictionary definitions for mono


  1. short for monophonic
  1. monophonic sound; monophony


before a vowel mon-

combining form
  1. one; singlemonochrome; monorail
  2. indicating that a chemical compound contains a single specified atom or groupmonoxide

Word Origin

from Greek monos
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 mono

1959 as a shortening of monophonic; earlier used among printers for "monotype machine" (c.1925) and generally for monochrome (motorcar, etc.), 1940s. From 1964 as short for mononucleosis.


word-forming element meaning "one, alone; containing one (atom, etc.)," from Greek mono-, comb. form of monos "single, alone," from PIE root *men- "small, isolated" (cf. Greek manos "rare, sparse," Armenian manr "thin, slender, small," and perhaps English minnow).

Online Etymology Dictionary, © 2010 Douglas Harper

mono in Medicine


  1. Infectious mononucleosis.


  1. One; single; alone:monomorphic.
  2. Monomolecular; monatomic:monolayer.
  3. Containing one atom, molecule, or group:monomer.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

mono in Science


  1. A prefix that means “one, only, single,” as in monochromatic, having only one color. It is often found in chemical names where it means “containing just one” of the specified atom or group, as in carbon monoxide, which is carbon attached to a single oxygen atom.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.