Meaning of EQUIVALENCE in English


ə̇ˈkwiv(ə)lən(t)s, ēˈ- noun

also equiv·a·len·cy -nsē, -si

( plural equivalences also equivalencies )

Etymology: Middle French & Medieval Latin; Middle French equivalence, from Medieval Latin aequivalentia, from Late Latin aequivalent-, aequivalens + Latin -ia -y


a. : the state or property of being equivalent : exchangeability, correspondence

the equivalence of paper money and coins

the equivalence between the hero's career and that of the author

: equatability

the equivalence of mass and energy

: geologic contemporaneity

time equivalency of the Sly Gap to a portion of the Devonian of Iowa is suggested by new paleological evidence — Journal of Geology

b. : an equivalent or an instance of equivalence

a series of logical equivalences

2. logic

a. : sameness in truth value ; specifically : the logical relationship holding between two statements if they are either both true or both false — called also material equivalence ; compare biconditional

b. : mutual deducibility or reciprocal entailment ; specifically : the relationship holding between two statements if to affirm one and to deny the other would result in a contradiction — called also logical equivalence, strict equivalence

3. : equality in metrical value of a regular foot and one in which there are substitutions (as of a long syllable for two short syllables in quantitative verse or of two or more light unaccented syllables for the normal unaccented syllable in accentual or syllabic verse)

Webster's New International English Dictionary.      Новый международный словарь английского языка Webster.