[ ir-i-doo-suh-buhl, -dyoo- ]
/ ˌɪr ɪˈdu sə bəl, -ˈdyu- /
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not reducible; incapable of being reduced or of being diminished or simplified further: the irreducible minimum.
incapable of being brought into a different condition or form.
  1. of or relating to a polynomial that cannot be factored.
  2. of or relating to a group that cannot be written as the direct product of two of its subgroups.



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“Was” is used for the indicative past tense of “to be,” and “were” is only used for the subjunctive past tense.

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Origin of irreducible

First recorded in 1625–35; ir-2 + reducible

OTHER WORDS FROM irreducible

ir·re·duc·i·bil·i·ty, ir·re·duc·i·ble·ness, nounir·re·duc·i·bly, adverb
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2021

Example sentences from the Web for irreducible

British Dictionary definitions for irreducible

/ (ˌɪrɪˈdjuːsɪbəl) /


not able to be reduced or lessened
not able to be brought to a simpler or reduced form
  1. (of a polynomial) unable to be factorized into polynomials of lower degree, as (x ² + 1)
  2. (of a radical) incapable of being reduced to a rational expression, as √(x + 1)

Derived forms of irreducible

irreducibility or irreducibleness, nounirreducibly, adverb
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

Medical definitions for irreducible

[ ĭr′ĭ-dōōsə-bəl ]


Impossible to reduce to a desired, simpler, or smaller form or amount.
Incapable of being made chemically simpler, or of being replaced, hydrogenated, or reduced in positive charge.

Other words from irreducible

ir′re•duc′i•bili•ty n.ir′re•duci•bly adv.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.