[ ih-kwiv-uh-luhns or, for 3, ee-kwuh-vey-luhns ]
/ ɪˈkwɪv ə ləns or, for 3, ˌi kwəˈveɪ ləns /
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noun Also equivalency (for defs. 1, 2).

the state or fact of being equivalent; equality in value, force, significance, etc.
an instance of this; an equivalent.
Chemistry. the quality of having equal valence.
Logic, Mathematics.
  1. Also called material implication. the relation between two propositions such that the second is not false when the first is true.
  2. Also called material equivalence. the relation between two propositions such that they are either both true or both false.
  3. the relation between two propositions such that each logically implies the other.


(of a logical or mathematical relationship) reflexive, symmetrical, and transitive.



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On the farm, the feed for chicks is significantly different from the roosters’; ______ not even comparable.

Origin of equivalence

1535–45; <Middle French <Medieval Latin aequivalentia, equivalent to Latin aequivalent-equivalent + -ia-ia; see -ence
non·e·quiv·a·lence, noun
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2021

British Dictionary definitions for equivalence



/ (ɪˈkwɪvələns) /


the state of being equivalent or interchangeable
maths logic
  1. the relationship between two statements, each of which implies the other
  2. Also called: biconditional the binary truth-function that takes the value true when both component sentences are true or when both are false, corresponding to English if and only if . Symbol: ≡ or ↔, as in –(pq) ≡ – p ∨ – q
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
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