[in-kloo-zhuh n]
See more synonyms for inclusion on
  1. the act of including.
  2. the state of being included.
  3. something that is included.
  4. Biology. a body suspended in the cytoplasm, as a granule.
  5. Mineralogy. a solid body or a body of gas or liquid enclosed within the mass of a mineral.
  6. Petrography. xenolith.
  7. Logic, Mathematics. the relationship between two sets when the second is a subset of the first.

Origin of inclusion

1590–1600; 1945–50 for def 7; < Latin inclūsiōn- (stem of inclūsiō) a shutting in, equivalent to inclūs(us) (see incluse) + -iōn- -ion
Related formsnon·in·clu·sion, nounpre·in·clu·sion, nounre·in·clu·sion, noun Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for noninclusion


  1. the act of including or the state of being included
  2. something included
  3. geology a solid fragment, liquid globule, or pocket of gas enclosed in a mineral or rock
  4. maths
    1. the relation between two sets that obtains when all the members of the first are members of the secondSymbol: XY
    2. strict inclusion or proper inclusionthe relation that obtains between two sets when the first includes the second but not vice versaSymbol: XY
  5. engineering a foreign particle in a metal, such as a particle of metal oxide
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 noninclusion



c.1600, from Latin inclusionem (nominative inclusio) "a shutting up, confinement," noun of action from past participle stem of includere (see include).

Online Etymology Dictionary, © 2010 Douglas Harper

noninclusion in Medicine


  1. A nonliving mass, such as a droplet of fat, in the cytoplasm of a cell.
  2. The process by which a foreign or heterogenous structure is misplaced in another tissue.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.