• synonyms


noun, plural i·sos. Television Slang.
  1. isolated camera.
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Origin of iso

by shortening; cf. -o


  1. incentive stock option.
  2. International Standardization Organization.
  3. the numerical exposure index of a photographic film under the system adopted by the International Standardization Organization, used to indicate the light sensitivity of the film's emulsion.
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  1. a combining form meaning “equal,” used in the formation of compound words: isochromatic; in chemistry, used in the names of substances which are isomeric with the substance denoted by the base word: isocyanic acid.
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Also especially before a vowel, is-.

Origin of iso-

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

Examples from the Web for iso

Historical Examples

  • But it is much more quiet and pleasant than other Japanese bathing resorts I have seen—such as iso.

    The Life and Letters of Lafcadio Hearn, Volume 2

    Elizabeth Bisland

British Dictionary definitions for iso


  1. International Organization for Standardization
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Word Origin

Greek isos equal; often wrongly thought to be an abbreviation for International Standards Organization


before a vowel is-

combining form
  1. equal or identicalisomagnetic
  2. indicating that a chemical compound is an isomer of a specified compoundisobutane; isocyanic acid
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Word Origin

from Greek isos equal
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 iso


word-forming element meaning "equal, similar, identical; isometric," from comb. form of Greek isos "equal to, the same as" (e.g. isometor "like one's mother"). Used properly only with words of Greek origin; the Latin equivalent is equi- (see equi-).

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Online Etymology Dictionary, © 2010 Douglas Harper

iso in Medicine


  1. Equal; uniform:isobar.
  2. Isomeric:isopropyl.
  3. Characterized by sameness with respect to species:isoantigen.
  4. Characterized by sameness with respect to genotype:isograft.
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The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

iso in Science


  1. An organization, the International Organization for Standardization, that sets standards in many businesses and technologies, including computing and communications. The term ISO is not an abbreviation, but instead derives from the Greek word īsos, meaning equal.
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  1. A prefix that means “equal,” as in isometric, “having equal measurements.”
  2. A prefix used to indicate an isomer of an organic compound, especially a branched isomer of a compound that normally consists of a straight chain. The isomer is characterized by a Y-shaped branch at the end of the chain that consists of two “prongs”. Each prong consists of one carbon atom. Thus isopentane contains five carbon atoms like normal pentane, but arranged as a chain of three carbons plus a Y-shaped branch of two carbons at the end.
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The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.