Try Our Apps


Avoid these words. Seriously.


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 Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2018.
Cite This Source
British Dictionary definitions for mono-


combining form
one; single: monochrome, monorail
indicating that a chemical compound contains a single specified atom or group: monoxide
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
Cite This Source
Word Origin and History for mono-

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
Cite This Source
mono- in Medicine

mono- or mon-

  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.
Cite This Source
mono- in Science
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 © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source

Word of the Day

Nearby words for mono-

Difficulty index for mono-

Few English speakers likely know this word

Word Value for mono

Scrabble Words With Friends